Grid framework structure

ABSTRACT

An earthquake restraint grid framework structure includes a grid framework structure for supporting a load handling device operative to move one or more containers in a stack. The grid framework structure includes intersecting grid members arranged to form a grid having plural f substantially rectangular frames in a horizontal plane, each of the substantially rectangular frames constituting a grid cell. The grid is supported by plural upright columns at each of the intersections of grid members to form a plurality of vertical storage locations for containers to be stacked between the upright columns and be guided in a vertical direction through the substantially rectangular frames. An exoskeleton includes plural vertical frame columns braced by at least one bracing member, the grid being further supported by the exoskeleton to form a seismic restraint system (SFRS).

FIELD OF INVENTION

The present invention relates to the field of remotely operated loadhandling devices on tracks located on a grid framework structure forhandling storage containers or bins stacked in the grid frameworkstructure, more specifically to a grid framework structure forsupporting the remotely operated load handling devices.

BACKGROUND

Storage systems comprising a three-dimensional storage grid structure,within which storage containers/bins are stacked on top of each other,are well known. PCT Publication No. WO2015/185628A (Ocado) describes aknown storage and fulfilment system in which stacks of bins orcontainers are arranged within a grid framework structure. The bins orcontainers are accessed by load handling devices remotely operative ontracks located on the top of the grid framework structure. A system ofthis type is illustrated schematically in FIGS. 1 to 3 of theaccompanying drawings.

As shown in FIGS. 1 and 2 , stackable containers, known as bins orcontainers 10, are stacked on top of one another to form stacks 12. Thestacks 12 are arranged in a grid framework structure 14 in a warehousingor manufacturing environment. The grid framework is made up of aplurality of storage columns or grid columns. Each grid in the gridframework structure has at least one grid column for storage of a stackof containers. FIG. 1 is a schematic perspective view of the gridframework structure 14, and FIG. 2 is a top-down view showing a stack 12of bins 10 arranged within the framework structure 14. Each bin 10typically holds a plurality of product items (not shown), and theproduct items within a bin 10 may be identical, or may be of differentproduct types depending on the application.

The grid framework structure 14 comprises a plurality of upright membersor upright columns 16 that support horizontal members 18, 20. A firstset of parallel horizontal grid members 18 is arranged perpendicularlyto a second set of parallel horizontal grid members 20 and arranged in agrid pattern to form a grid structure comprising a plurality of gridcells or grid spaces supported by the upright members 16. The members16, 18, 20 are typically manufactured from metal and typically weldingor bolted together or a combination of both. The bins 10 are stackedbetween the members 16, 18, 20 of the grid framework structure 14, sothat the grid framework structure 14 guards against horizontal movementof the stacks 12 of bins 10, and guides vertical movement of the bins10.

The top level of the grid framework structure 14 includes rails 22arranged in a grid pattern across the top of the stacks 12. Referringadditionally to FIG. 3 , the rails 22 support a plurality of loadhandling devices 30. A first set 22 a of parallel rails 22 guidemovement of the robotic load handling devices 30 in a first direction(for example, an X-direction) across the top of the grid frameworkstructure 14, and a second set 22 b of parallel rails 22, arrangedperpendicular to the first set 22 a, guide movement of the load handlingdevices 30 in a second direction (for example, a Y-direction),perpendicular to the first direction. In this way, the rails 22 allowmovement of the robotic load handling devices 30 laterally in twodimensions in the horizontal X-Y plane, so that a load handling device30 can be moved into position above any of the stacks 12.

A known load handling device 30 shown in FIGS. 4 and 5 comprises avehicle body 32 is described in PCT Patent Publication No. WO2015/019055(Ocado), hereby incorporated by reference, where each load handlingdevice 30 only covers one grid space of the grid framework structure 14.Here, the load handling device 30 comprises a wheel assembly comprisinga first set of wheels 34 consisting a pair of wheels on the front of thevehicle body 32 and a pair of wheels 34 on the back of the vehicle 32for engaging with the first set of rails or tracks to guide movement ofthe device in a first direction and a second set of wheels 36 consistingof a pair of wheels 36 on each side of the vehicle 32 for engaging withthe second set of rails or tracks to guide movement of the device in asecond direction. Each of the set wheels are driven to enable movementof the vehicle in X and Y directions respectively along the rails. Oneor both sets of wheels can be moved vertically to lift each set ofwheels clear of the respective rails, thereby allowing the vehicle tomove in the desired direction.

The load handling device 30 is equipped with a lifting device or cranemechanism to lift a storage container from above. The crane mechanismcomprises a winch tether or cable 38 wound on a spool or reel (notshown) and a grabber device 39. The lifting device comprise a set oflifting tethers 38 extending in a vertical direction and connectednearby or at the four corners of a lifting frame 39, otherwise known asa grabber device (one tether near each of the four corners of thegrabber device) for releasable connection to a storage container 10. Thegrabber device 39 is configured to releasably grip the top of a storagecontainer 10 to lift it from a stack of containers in a storage systemof the type shown in FIGS. 1 and 2 .

The wheels 34, 36 are arranged around the periphery of a cavity orrecess, known as a container-receiving space 40, in the lower part. Therecess is sized to accommodate the container 10 when it is lifted by thecrane mechanism, as shown in FIG. 5 (a and b). When in the recess, thecontainer is lifted clear of the rails beneath, so that the vehicle canmove laterally to a different location. On reaching the target location,for example another stack, an access point in the storage system or aconveyor belt, the bin or container can be lowered from the containerreceiving portion and released from the grabber device.

However, the grid framework structure is subjected to various externaland internal forces. These include but are not limited to groundmovement which can be attributed to the composition of the ground orsoil type, forces developed by the movement of the load handling deviceson the grid framework structure which can weight in excess of 100 kg,movement as a result of nearby constructions or moving vehicles such astrains or even during an earthquake or storm. It is paramount to keepthe individual elements within the grid framework structure intact as aresult of such external forces experienced by the grid framework.

To ensure stability of the grid framework structure, prior art storagesystems are largely dependent on various supports and bracing arrangedwithin or at least partly along the periphery of the grid. However, theuse of various supports and bracing (anti-movement braces) to stabilisethe grid framework structure from internal and external forces isdisadvantageous for a number of reasons. The grid framework structureoccupies space or area which could be utilised by the grid to storecontainers; in that it prevents optimum usage of available space or areafor the storage of containers. The need of a supporting structure maylimit the available options for positioning of the grid frameworkstructure since any auxiliary grid supporting structure often requiresconnection to a surrounding structure such as the inner walls of abuilding and the requirement of a supporting structure that is not costefficient.

WO2019/101367 (Autostore Technology AS) teaches a grid supportingstructures for integration in a storage grid structure of an automatedstorage system arranged. The grid supporting structure is made up offour storage columns interconnected by multiple vertically inclinedsupport struts. The storage column profiles has a cross-sectioncomprising a hollow centre section and four corner sections, each cornersection comprises two perpendicular bin guiding plates for accommodatinga corner of a storage bin. The support struts has a width which allowsthem to fit in between two parallel guiding plates so as to notcompromise the ability of the storage columns to accommodate a stack ofcontainers or storage bins.

An alternative grid framework structure is thus required that minimisesthe impact of the available space or area for the storage of containersso as to provide a free-standing storage grid or at least requiring aless extensive auxiliary grid support structure.

Much of the world's population is located along seismic fault lines orin the paths of powerful storms such as hurricanes and tornadoes.Locating the grid frame structure in such areas are at risk ofstructural damage from seismic and storm events as the current gridframework structure may not hold the grid structure together. Powerfulseismic and storm events may result in the failure of their structuralintegrity e.g. as a result in the inability of the structural fastenersto keep the grid firmly attached to the upright members. Earthquakes canbe labelled into four categorises labelled as Type A, B, C, or Ddepending on the severity of the earthquake, whereby Type A isconsidered the least powerful earthquake and Type D is considered themost powerful earthquake. Type A - D can be graded by their spectralacceleration which is the maximum acceleration measured in g that anobject, above ground level, will experience during an earthquake. Type Dconsidered to represent the most powerful seismic event and typically,has a measured spectral acceleration in the region 0.5 g to 1.83 g(short period spectral response acceleration SDS seehttps://www.fegstructural.com/seismic-design-category-101/) and is theresult of most failure of buildings. As powerful seismic events act on astructure, the three dimensional dynamic forces compromise thestructural fasteners holding the grid framework structure together,causing them to work their way loose or out of the members in which theyare embedded or, if they remain in place, they may tear their waythrough a structural fastener.

Many jurisdictions, such as the US states, have passed laws mandatingthat all new buildings, residential or commercial be constructed withcertain seismic bracing features incorporated therein. A grid frameworkstructure comprises internal bracing features incorporated within thegrid framework structure whereby one or more of the upright members arebraced together by one or more bracing members or bracing towers isshown in FIG. 6 a . Typically, the bracing members are distributedinternally throughout the grid framework structure. The distribution ofthe internal bracing is largely dependent on the size of the gridframework structure, the ground condition and the environmentalcondition such as temperature. However, whilst the grid frameworkstructure is able to withstand very low level seismic events having aspectral acceleration less than 0.3 g, presently there are no earthquakerestraint system for a grid framework structure that is able towithstand more powerful Type C and Type C seismic events categorised bya spectral acceleration in the region of 0.5 g to 1.83 g.

An earthquake restraint grid framework structure is thus required thatis able to withstand powerful seismic events.

This application claims priority from UK patent application no.GB2003047.4 filed 3 Mar. 2020, the content of that application herebybeing incorporated by reference.

SUMMARY OF INVENTION

Whilst the current grid framework structure is able to withstandrelatively small levels of ground movement usually less than 0.33 gspectral acceleration (short period spectral response acceleration SDSsee https://www.fegstructural.com/seismic-design-category-101/), thiscannot be said for ground movement in excess of 0.33 g that is usuallyrepresentative of Type C and Type D seismic events. The joints linkingthe grid members and the upright columns together which are largelybolted together would tend to loosen and in an extreme case separateaffecting the structure of the grid framework structure. Even though oneor more braced towers can be incorporated amongst the upright columns toimprove the stability of the grid framework structure, this may not beenough to maintain the stability of the grid framework structure in anevent of a Type C and Type D seismic event. The present invention hasmitigated the above problem by supporting the grid framework structureby an exoskeleton. The exoskeleton provides an additional level ofsupport to the grid framework structure from seismic event. Morespecifically, the present invention provides an earthquake restraintgrid framework structure comprising a grid framework structure forsupporting a load handling device operative to move one or morecontainers in a stack, said grid framework structure comprising:

a series of intersecting grid members arranged to form a grid comprisinga plurality of substantially rectangular frames in a horizontal plane,each of the substantially rectangular frames constituting a grid cell,said grid is supported by a plurality of upright columns at each of theintersections of the series of grid members to form a plurality ofvertical storage locations for containers to be stacked between theupright columns and be guided by the upright column in a verticaldirection through the plurality of substantially rectangular frames,

characterised in that the earthquake restraint grid framework structurefurther comprises:

an exoskeleton comprising a plurality of vertical frame columns 218braced by at least one bracing member, said grid is further supported bythe exoskeleton to form a seismic restraint system (SFRS).

The exoskeleton comprises a perimeter bracing structure around the gridframework structure to provide another level of lateral support to thegrid framework structure. The perimeter bracing structure is supportedby the plurality of vertical frame columns to form the seismic restraintsystem (SFRS). More specifically, the at least one bracing memberextends from each of the plurality of vertical columns to form aperimeter bracing structure to further support the grid. Preferably, thegrid comprises a border or an outer zone such that the border or outerzone of the grid is supported by the exoskeleton.

For the purpose of the present invention, the grid is bordered by anouter zone around the periphery of the grid. The width of the border orouter zone is at least one grid cell, preferably a single grid cell. Thegrid is supported at or within the border such that the least onebracing member is inwardly positioned within the border or outer zone ofthe grid. For the purpose of the present invention, the term “support”is construed to mean any mechanical connection. In this case, themechanical connection between the grid at the border with the at leastone bracing member. Preferably, the at least one bracing member isinwardly positioned from the edge of the grid such that the outer zoneor border of the grid extends or spans across the at least one bracingmember. By supporting the grid mid-cell within the border of the grid,the bending moments experienced by the support is minimised since thebending moments are largely at the edge of the grid where the gridmember intersect. Whilst not ideal, equally covered by the presentinvention, the border or outer zone of the grid constitutes the edge ofthe grid such that the grid is supported around the periphery of thegrid by a perimeter bracing structure.

The present applicant has realised that by supporting the grid frameworkstructure within the exoskeleton, lateral forces developed within thegrid framework structure are absorbed by the exoskeleton. Theexoskeleton can act as a sacrificial structure of the seismic gridframework structure such that components of the exoskeleton issacrificed to maintain the structural integrity of the grid frameworkstructure. During a seismic event, the grid at the top of the uprightcolumns is subjected to side to side movement as a result of groundmovement. As the grid members are joined at the intersections whereadjacent grid members cross at the upright columns, supporting the gridaround the periphery of the grid either at the edge of the grid orwithin the borders of the grid helps to mitigate damage to the gridframework structure as a result of seismic events.

In the present invention, the border or outer zone of the grid issupported around the grid by the exoskeleton comprising a plurality ofvertical frame columns braced by at least one bracing member extendingfrom each of the plurality of vertical frame columns to form a seismicforce restraint system (SFRS), i.e. the SFRS forms a moment resistingframe. The SFRS comprising the exoskeleton supports the grid during apowerful seismic event by supporting the grid framework structure. Forthe purpose of the present invention, supported is construed to includemechanically connected either directly or indirectly to the gridframework structure. For example, the grid is supported by the perimeterbracing structure of the present invention by mechanically connectingthe grid around the periphery of the grid at the edge of the grid orwithin its border to the perimeter bracing structure of the presentinvention and the perimeter bracing structure is supported by theplurality of vertical columns to form the exoskeleton, i.e. theexoskeleton comprises the perimeter bracing structure.

Preferably, the series of intersecting grid members are rigidlyconnected together at the intersections to form at least one Vierendeeltruss assembly. As is commonly known in the art, a Vierendeel trussassembly is a series of rectangular frames which achieves stability bythe rigid connection of vertical web members to the top and bottomchords. The Vierendeel truss transfers shear from the chords by bendingmoments at the joints and finally by bending moments in the verticalwebs. As the grid of the present invention lies in a horizontal plane,the grid members extending in a first direction and in a seconddirection (the second direction being perpendicular to the firstdirection), represent the web members and the top and bottom chords ofthe Vierendeel truss assembly. As a result all of members of the gridare combined stress members in which axial, shear and bending stressesexist.

Preferably, the grid is attached between pairs of the bracing membersalong the border of the grid to form at least one Vierendeel trussassembly so as to provide lateral support of the grid frameworkstructure in a side-to-side direction. Optionally, the at least onebracing member is a horizontal frame beam, said horizontal frame beamextends between at least two of the plurality of vertical frame columnsto form a drag strut. Optionally, the at least one bracing member is adiagonal bracing member, said diagonal bracing member extends between atleast two of the plurality of vertical frame columns. For the purpose ofthe present invention, the at least one bracing member can be ahorizontal frame beam or strut that extend between two vertical framecolumns to form a drag strut or at least one diagonal bracing member ora combination thereof. A drag strut, drag truss or collector is a singleelement or component designed to transmit lateral loads to lateral loadresisting systems that are parallel to the applied force. Here, thehorizontal frame beams acts as a drag strut or collector that isdesigned to resist and to transmit lateral loads. In accordance withASCE 7 (American Society of Civil Engineers), a drag strut is astructural element (could be a truss) installed parallel to an appliedload that collects and transfers diaphragm shear forces to thevertical-force-resisting element or distributes forces within thediaphragm. Properly designed, drag strut trusses and their connectionswill transfer lateral loads to the foundation and then safely into theground.

Preferably, the diagonal member comprises a first diagonal member and asecond diagonal member. Preferably, the at least one bracing memberfurther comprises a horizontal frame beam, and wherein the firstdiagonal bracing member, the second diagonal bracing member and thehorizontal frame beam are arranged to form a K brace, said K brace isdisposed between the at least two of the plurality of vertical framecolumns. Where the at least one bracing member is a diagonal bracingmember, the at least one bracing member can be arranged into a K braceconnected between two vertical frame columns. Preferably, each of the atleast two vertical frame columns has a bottom end and a top end, andeach of the first and second diagonal bracing members having a first endconstituting its lower end and a second end constituting its upper end,the first and the second diagonal bracing members are arranged withtheir lower end adjacent the bottom end of each of the at least twovertical frame columns and inclined upwardly with their upper endsadjacent each other at a peak such that the peak meet at a point on thehorizontal frame beam to form a K brace. Alternatively or in addition,the at least one bracing member is a cross brace. Preferably, the firstdiagonal bracing member and the second diagonal bracing member arearranged in a cross brace, said cross brace is disposed between the atleast two of the plurality of vertical frame columns 218 such that theat least two vertical frames columns are joined together by the crossbrace. More preferably, each of the least two vertical frame columns hasouter ends, the first diagonal bracing and the second diagonal bracingmember are arranged in a cross shape, each of the first diagonal bracingand the second diagonal bracing member having opposing ends, wherein theat least two of the plurality of vertical frame columns are joinedtogether by the cross brace such that the outer ends of the at least twovertical frame columns is connected to the opposing ends of the firstand second diagonal bracing members.

During a powerful seismic event, the exoskeleton can comprise a K-braceor a cross-brace work in tension and compression in the SFRS andtherefore, are subjected to the greatest lateral forces. In extremeseismic events, the diagonal braces may buckle as it absorbs thelaterals forces from the grid. As the SFRS of the present inventionforms an exoskeleton around the grid framework structure, components ofthe SFRS such at the diagonal bracing are easily replaceable.

Preferably, the SFRS of the present invention comprises a plurality ofvertical frame columns at the corners of the grid framework structure.The grid framework structure can be considered as a rectilinearassemblage of vertical or upright columns supporting a grid formed fromthe intersecting horizontal grid members, i.e. a four wall shaped 3dimensional framework. Preferably, the plurality of vertical framecolumns comprises four vertical frame columns arranged at four cornersof the grid framework structure and the at least one bracing memberextending longitudinally from each corner at the top of the fourvertical frame columns to form a substantially rectangular or squareperimeter frame within or around the border outer zone of the grid. Therectangular or square perimeter frame is supported by the vertical framecolumns at the corners of the grid framework structure to form theexoskeleton of the present invention. By having a rectangular or squareperimeter frame around the periphery of the grid, the grid is supportedaround its periphery by the perimeter frame. This could be either at theedges of the grid or at the borders around the grid. The at least onebracing member extending from each corner at the top of the fourvertical frame columns is a horizontal frame beam. Preferably, the gridis attached between pairs of the horizontal frame beams along the borderor outer zone of the grid to form at least one Vierendeel truss assemblyso as to provide lateral support of the grid framework structure in aside-to-side direction. Putting it another way, the grid is attached tothe horizontal frame beams extending from the vertical frame beams atthe corners of the grid framework along the edge or at the border of thegrid.

Preferably, the plurality of vertical frame columns further comprises atleast one vertical frame column disposed between at least two of thefour vertical frame columns at the corners of grid framework structureand the at least one bracing member extends between at least one of thefour of vertical frame columns 218 a at the corners of the gridframework structure 114 and the at least one of the plurality ofvertical frame columns 218 b between the at least two of the fourvertical frame columns 218 b at the corners of the grid frameworkstructure 114. As the grid framework structure can be considered as arectilinear assemblage of vertical or upright columns supporting a grid,the SFRS of the present invention can also be considered as a 3dimensional rectilinear assemblage of vertical frame columns at thecorners of the grid framework structure and horizontal frame beamsextending from the top of each of the vertical frame columns. By havinga vertical frame column that is intermediate between the vertical framecolumns at the corners of the grid framework structure and providing abrace between the vertical column between one of the corners of the gridframework structure and the intermediate vertical frame column, at leastone face of the SFRS is divided into a braced frame comprising at leastone diagonal brace and a drag strut. The diagonal braced frame and thedrag strut are either side of the intermediate vertical frame column.Preferably, the collection of the braced frame and the drag strut areprovided on all four faces of the SFRS of the present invention.

In comparison to bolting the grid members at the intersections wherethey cross which are susceptible to loosening in a powerful seismicevent, preferably the series of the grid members are welded at theirintersections. The welded joints at the intersections provides a moresturdy and rigid joint at the intersections where the grid memberscross. As the bending moments at transferred at the intersections,welding the grid members at the intersections, the joints are able toresist loads at the intersections.

Preferably, the at least one of the series of grid members is tubularbeam. The use of tubular beams to construct the grid members incomparison to other shaped beams provides more resistance to bendingsince the walls of the tubular beam are able to resist bending in alldirections.

Whilst welding the grid members at the junctions where the grid memberscross at the intersections provides a sturdy grid structure that resistbending moments, this presents a problem of constructing the gridframework structure on-site. Welding the grid members together on-siteor in-situ may fall foul of health and safety legislation due toexposure of welding fumes and being a fire risk. The present applicanthas mitigated this problem by sub-dividing the grid into sub-frames.Preferably, the grid is sub-divided into a plurality of interconnectedsub-frames, each of the plurality of interconnected sub-framescomprising at least one grid cell. By dividing the grid into sub-frameswhereby each of the sub-frames comprises at least one grid cell removesthe need to weld the grid members at the junctions where the gridmembers cross at the intersections. Each of the sub-frames can be joinedtogether to make up the grid of the present invention. Various methodscan be used to join adjacent sub-frames, these include but are notlimited to bolts or the use of other of mechanical fasteners, e.g.rivets. Since the bending moments are concentrated at the intersectionswhere the grid members cross at the upright columns, locating the jointfor fixing adjacent sub-frames together between the intersections(mid-cell) is not subjected to excessive bending moments. Preferably,adjacent sub-frames are joined together by a joint between theintersections, i.e. mid-cell. The bending moments are greatest at theintersections and decrease between the intersections to a minimum halfway between the intersections. Preferably, the joint is substantiallymid-way between the intersections. As a result, locating the jointlinking adjacent sub-frames together mid-way between the intersectionswhere the bending moments are the weakest, allows the joints to use lesssubstantially fasteners such as bolts or rivets. Preferably, adjacentsub-frames are bolted together by one or more bolts. Adjacent sub-framesare joined together so that connections mid-cell between theintersections of the adjacent sub-frames completes a grid cell.

To interconnect the plurality of vertical or upright columns at theirtop ends, preferably the grid comprises at least one spigot at theintersections receivable in an opening in the upright column. Each ofthe plurality upright columns have a cross-section profile comprising ahollow centre section and four corner sections in the form of twoperpendicular guiding plates. The hollow centre section is preferably abox section. The at least one spigot is sized to be received into thehollow cross section of the upright column.

To provide lateral support to the SFRS of the present invention,preferably, the at least one of the at least two vertical frame columnsis an I-beam. More preferably, each of the at least two vertical framecolumns are anchored to the ground (e.g. concrete foundation) by one ormore anchor bolts.

Preferably, a rail or track is mounted to the grid for guiding themovement of the load handling devices on the grid. More preferably, therail or track is mounted to the grid by a snap fit and/or a slide fitarrangement. The rail or track is mounted to the grid via a tracksupport that has a cross-sectional profile to accept the track or railin a snap-fit arrangement. The track support is preferably welded to thegrid members.

Preferably, a crash barrier comprising one or more impact absorbers,said crash barrier is mounted to at least a portion of the grid. Morepreferably, the crash barrier comprises a frame mounted to the at leastportion of the grid. Preferably, the frame comprises two or morevertical posts mounted to the edge of the grid. Connected between thevertical posts is a horizontal crash beam. The one or more impactabsorbers are mounted to the horizontal crash beam.

To dampen the ground movement during a seismic event, preferably atleast a portion of the grid is supported to the plurality of verticalcolumns 116 by one or more moveable joints such that the at leastportion of the grid 50 and the one or more of the vertical columns 116can move independently relative to each other during seismic activity.During a seismic event lateral movement of the vertical uprights as aresult of ground movement is absorbed by one or more moveable jointsinterposed between the plurality of vertical upright columns and thegrid. In other words, the grid is isolated from the vertical columns butstill is supported by the vertical columns so as to allow lateralmovement between the grid and the vertical upright columns.

The earthquake resistant grid framework structure of the presentinvention can be modularised so that adjacent modules can share at leasta portion of the SFRS or the exoskeleton of adjacent modules.Preferably, each of the two or more modular frames comprises anearthquake restraint grid framework structure of the present invention,wherein adjacent modular frames are arranged in the assembly to share atleast a portion of the SFRS between adjacent modular frames such thateach of the module frames comprises a grid comprising a predeterminednumber of grid cells supported by the exoskeleton. The versatility ofthe SFRS of the present invention to form an exoskeleton around the gridframework structure allows adjacent grid framework structures to shareportions of the perimeter bracing structure of an adjacent module. Eachof the modular frames comprises a predetermined number of grid cells.Adjacent modules can be joined together to increase the storage capacityof the grid framework structure. To share at least a portion of theSFRS, preferably, the grid of adjacent modular frames extends across theexoskeleton of adjacent modular frames. The exoskeleton of the presentinvention comprises a perimeter bracing structure substantially aroundthe grid. By sharing the exoskeleton between adjacent modular frames,the grid of adjacent modular frames share at least a portion of theperimeter bracing structure that is common between adjacent modularframes, e.g. vertical frame columns and the at least one bracing member.

The versatility and the resistance to bending moments of the SFRS of thepresent invention, other structural systems can be integrated intoperimeter bracing structure of the present invention. Preferably, atleast one mezzanine is disposed between two or more modular frames suchthat the grid of the two or more modular frames extends across the atleast one mezzanine. The mezzanine provide a service area within thegrid framework structure to accommodate a picking station and/or aservice station for servicing the load handling device and/or a chargestation for charging the rechargeable power source, e.g. a battery, onboard the load handling device. Preferably, the at least one mezzanineis supported by the two or more modular frames such that the mezzanineshares at least one vertical frame column common between the two or moreof the modular frames. To integrate a mezzanine within the gridframework structure, preferably the at least one mezzanine share atleast one vertical frame column common between the two or more of theadjacent modular frames. The at least two vertical frame columnssupporting the mezzanine can itself be braced to resist lateral forces.Preferably, at least two of the vertical frame columns shared by the atleast one mezzanine is braced by at least one bracing member. Morepreferably, the at least one bracing member is a diagonal bracingmember. By bracing the two vertical frame columns supporting themezzanine, the mezzanine can also provide structural support to theseismic grid framework structure.

To prevent the movement of the modular frames comprising the gridframework structure from being transmitted to the mezzanine, inparticular where the mezzanine is used as a pick station, preferably,the mezzanine is connected to the two or more modular frames by one ormore movement joints, such that the mezzanine and the one or moremodular frames can move independently relative to each other during aseismic activity. In other words, the mezzanine is isolated from themovement of the two or more modular frames and thereby, offeringincreased personal protection of the working areas surrounded by themezzanine.

In addition, to the grid of adjacent modular frames sharing theperimeter bracing structure common between the adjacent modular framessuch that adjacent grids are supported by the common perimeter bracingstructure, e.g. vertical frame columns and the at least one bracingmember, adjacent modular frames can also share a common crash barriermounted to the periphery of an assembly of one or more grids.

In another aspect of the present invention, a storage system is providedcomprising:

i) an earthquake restraint grid framework structure according to thepresent invention discussed above;

ii) a plurality of stacks of containers arranged in storage columnslocated below the grid, wherein each storage column is locatedvertically below the grid cell;

iii) a plurality of load handling devices for lifting and movingcontainers stacked in the stacks, the plurality of load handling devicesbeing remotely operated to move laterally on the grid above the storagecolumns to access the containers through the substantially rectangularframes, each of said plurality load handling devices comprises:

a) a wheel assembly for guiding the load handling device on the grid;

b) a container-receiving space located above the grid; and

c) a lifting device arranged to lift a single container from a stackinto the container-receiving space.

In a further aspect of the present invention, a storage system isprovided comprising:

i) an assembly of two or more modular frames, wherein each of the two ormore modular frames comprises an earthquake restraint grid frameworkstructure of the present invention;

ii) a plurality of stacks of containers arranged in storage columnslocated below the grid, wherein each storage column is locatedvertically below the grid cell;

iii) a plurality of load handling devices for lifting and movingcontainers stacked in the stacks, the plurality of load handling devicesbeing remotely operated to move laterally on the grid above the storagecolumns to access the containers through the substantially rectangularframes, each of said plurality load handling devices comprises:

a) a wheel assembly for guiding the load handling device on the grid;

b) a container-receiving space located above the grid; and

c) a lifting device arranged to lift a single container from a stackinto the container-receiving space.

Further features of the present invention will be apparent from thedetailed description with reference to the drawings.

DESCRIPTION OF DRAWINGS

Further features and aspects of the present invention will be apparentfrom the following detailed description of an illustrative embodimentmade with reference to the drawings, in which:

FIG. 1 is a schematic diagram of a grid framework structure according toa known system,

FIG. 2 is a schematic diagram of a top down view showing a stack of binsarranged within the framework structure of FIG. 1 .

FIG. 3 is a schematic diagram of a system of a known load handlingdevice operating on the grid framework structure.

FIG. 4 is a schematic perspective view of the load handling deviceshowing the lifting device gripping a container from above.

FIGS. 5(a) and 5(b) are schematic perspective cut away views of the loadhandling device of FIG. 4 showing (a) the container receiving space ofthe load handling device and (b) a container accommodating the containerreceiving space of the load handling device.

FIG. 6 a is a perspective view of the grid framework structure accordingto an embodiment of the present invention.

FIG. 6 b is a top plan view showing the layout of the grid frameworkstructure in a typical fulfilment centre according to an embodiment ofthe present invention.

FIG. 6 c is a side view model of a typical fulfilment centre accordingto an embodiment of the present invention.

FIG. 6 d is a perspective view showing the arrangement of the uprightcolumns forming vertical storage locations or grid columns forcontainers to be stacked between the upright columns according to anembodiment of the present invention.

FIG. 6 e is an illustration of the panelling around the grid frameworkstructure.

FIG. 6 f is an illustration of a mesh panelling according to anembodiment of the present invention.

FIG. 6 g is a perspective view of the panelling and supporting structureaccording to an embodiment of the present invention.

FIG. 7 is a schematic representation of cross-sectional top down view ofthe arrangement of the upright columns or members in the grid frameworkstructure according to an embodiment of the present invention.

FIG. 8 is a perspective view of a storage space or column within a gridframework structure according to an embodiment of the present invention.

FIG. 9 is a perspective view of an adjustable foot according to anembodiment of the present invention.

FIG. 10 shows a perspective view of the insert portion or cap of theadjustable foot according to the embodiment of the present invention.

FIG. 11 (a to c) is a schematic view of a braced tower according to anembodiment of the present invention.

FIG. 12 is a plan view of the distribution of the braced tower withinthe grid framework structure according to an embodiment of the presentinvention.

FIG. 13 is a schematic view of a flange connecting the diagonal bracesto the braced tower according to the embodiment of the presentinvention.

FIG. 14 is an expanded view of the braced tower showing the connectionof the diagonal braces to the middle upright column according to anembodiment of the present invention.

FIG. 15 is an expanded view of the braced tower showing the connectionof the diagonal braces to the middle upright column according to anotherembodiment of the present invention.

FIG. 16 a is a side view of an anchor foot according to a secondembodiment of the present invention.

FIG. 16 b is a top down view of the anchor foot according to the secondembodiment of the present invention

FIG. 17 is a perspective view showing the pattern the grid elements ofthe grid according to an embodiment of the present invention.

FIG. 18 is a perspective view of the cap plate for joining adjacent gridelements at the intersections according to an embodiment of the presentinvention

FIG. 19 is a perspective view of the cap plate linking adjacent gridelements by connecting the end of a grid element at the intersectionsaccording to an embodiment of the present invention.

FIG. 20 is a perspective view of the cap plate linking adjacent gridelements at the intersections by connecting a centre section of a gridelement and an end of an adjacent grid element according to theembodiment of the present invention.

FIG. 21 is a perspective view of the cap plate fitted to an uprightcolumn for connecting adjacent grid elements together at theintersection where the grid elements cross according to an embodiment ofthe present invention.

FIG. 22 is a perspective view showing the pattern of the grid elementsat the intersections according to an embodiment of the presentinvention.

FIG. 23 is a perspective view of a grid element or track supportaccording to an embodiment of the present invention.

FIG. 24 is a perspective cross sectional view along the line X-X in FIG.20 showing the joint between adjacent grid elements at the intersectionsaccording to an embodiment of the present invention.

FIG. 25 is a perspective view of a track element according to anembodiment of the present invention.

FIG. 26 is a perspective view of the arrangement of the track elementsat the intersection where the grid elements cross according to anembodiment of the present invention.

FIG. 27 is a perspective view of a seismic grid framework structureaccording to a first embodiment of the present invention.

FIG. 28 is a perspective view of the seismic grid framework structureaccording to a second embodiment of the present invention.

FIG. 29 is a perspective view showing the grid being supported at theborder of the seismic grid framework structure shown in FIG. 27 and FIG.28 according to an embodiment of the present invention.

FIG. 30 is a top plan view of the seismic grid framework structureshowing the arrangement of braces according to a first embodiment of thepresent invention.

FIG. 31 is a top plan view of the seismic grid framework structureshowing the arrangement of the braces according to another embodiment ofthe present invention.

FIG. 32 is a perspective cross-sectional view of the seismic gridframework structure showing the cross-sectional profile of the gridmembers according to an embodiment of the present invention.

FIG. 33 is the distribution of the bending moments across the grid whenfunctioning as a

Vierendeel truss.

FIG. 34 is a schematic view of the arrangement of sub-frames making upthe grid of the seismic grid framework structure according to anembodiment of the present invention

FIG. 35 is a schematic top view of a sub-frame of the grid of theseismic grid framework structure according to the embodiment of thepresent invention.

FIG. 36 is a schematic underside view of the sub-frame of the grid ofthe seismic grid framework structure according to the embodiment of thepresent invention.

FIG. 37 is a schematic view of a sub-frame at the edge of the gridshowing connection plates for connecting to the SFRS according to theembodiment of the present invention.

FIG. 38 is a top plan view of a sub-frame being supported by the SFRSaccording to the embodiment of the present invention.

FIG. 39 is a cross-sectional view showing the engagement of the track tothe track support of the grid element of the seismic grid frameworkstructure according to an embodiment of the present invention.

FIG. 40 is a top plan view showing modularity of the seismic gridframework structure according to an embodiment of the present invention.

FIG. 41 is a schematic view of a known fulfilment centre showing amezzanine between adjacent grid framework structures.

FIG. 42 is a cross-sectional view of modular grid framework structuresincorporating an integrated mezzanine according to an embodiment of thepresent invention.

FIG. 43 is a top plan view of a fulfilment centre incorporating amezzanine according to the embodiment of the present invention.

FIG. 44 illustrates a mezzanine connected to the supporting structure byone or more movement joints according to an embodiment of the presentinvention.

FIG. 45 illustrates one possible embodiment of a movement joint.

FIG. 46 illustrates a possible configuration of the movement jointconnected to the mezzanine.

FIG. 47 illustrates a different configuration of the movement jointconnected to the mezzanine.

FIG. 48 illustrates a different view of the configuration of FIG. 47 .

FIG. 49 is a perspective view of a crash barrier at the edge of the gridaccording to an embodiment of the present invention.

DETAILED DESCRIPTION

Grid Framework Structure

FIG. 6 a shows a perspective view of a grid framework structure 114according to an embodiment of the present invention. The basiccomponents of the grid framework structure 114 according to the presentinvention comprises a grid 50 lying in a horizontal plane mounted to aplurality of upright columns or upright members 116. The terms “uprightmember(s)” and “upright column(s)” and “vertical column(s)” are usedinterchangeably in the description to mean the same thing or feature. Asshown in FIG. 6 a , the grid 50 comprises a series of horizontalintersecting beams or grid members 118, 120 arranged to form a pluralityof rectangular frames 54, more specifically a first a set of gridmembers 118 extend in a first direction x and a second set of gridmembers 120 extend in a second direction y, the second set of gridmembers 120 running transversely to the first set of grid members 118 ina substantially horizontal plane. The first and the second set of gridmembers supports a first and a second set of tracks 57 a, 57 brespectively for a load handling device to move one or more containerson the grid framework structure. For the purpose of explanation of thepresent invention, the intersections 56 constitute nodes of the gridstructure. Each of the rectangular frames 54 constitute a grid cell andare sized for a remotely operated load handling device or bot travellingon the grid framework structure to retrieve and lower one or morecontainers stacked between the upright columns 116. The grid 50 israised above ground level by being mounted to the plurality of uprightcolumns 116 at the intersections or nodes 56 where the grid members 118,120 cross so as to form a plurality of vertical storage locations 58 forcontainers to be stacked between the upright columns 116 and be guidedby the upright columns 116 in a vertical direction through the pluralityof substantially rectangular frames 54. For the purpose of the presentinvention, a stack of containers can encompass a plurality of containersor one or more containers. The grid framework structure 114 can beconsidered as a rectilinear assemblage of upright columns 116 supportingthe grid 50 formed from intersecting horizontal grid members 118, 120,i.e. a four wall shaped framework. Two or more of the upright columnsare braced by at least one diagonal bracing member to provide one ormore braced towers 80 within the grid framework structure 114. For thepurpose of the present invention, the term “vertical upright column”,“upright column” and “upright member” are used interchangeably throughthe description.

Upon receipt of the order, a load handling device operative to move onthe tracks is instructed to pick up a storage bin containing the item ofthe order from a stack in the grid framework structure and transport thestorage bin to a pick station whereupon the item can be retrieved fromthe storage bin and transferred to one or more delivery containers.Typically, the pick station comprises a container transport assembly totransport one or more containers to an access station where the contentsof the containers can be accessed. The container transport assembly istypically a conveyor system comprising multiple adjacent conveyor units.

A typical layout of a fulfilment centre for fulfilment of an order isshown in FIG. 6 b . The fulfilment centre comprises two distinct gridareas known as an ambient grid area 114 b and a chill grid area 114 c.Each of the ambient grid area 114 b and the chill grid area 114 ccomprises a grid framework structure, i.e. the ambient grid area 114 bcomprises a first grid framework structure 114 b and the chill grid area114 c comprises a second grid framework structure 114 c. For the purposeof the present invention, the ambient grid area 114 b stores food andgrocery commodities at an ambient controlled temperature. For thepurpose of the present invention, the ambient controlled temperaturecoves a range between substantially 4° C. to substantially 21° C.,preferably substantially 4° C. to substantially 18° C. Likewise, thechill grid area 114 c stores food and grocery commodities at a chilledtemperature. For the purpose of the present invention, the chilledtemperature covers a range between substantially 0° C. to substantially4° C. The two grid areas—ambient and chill—are filled with containers(otherwise known as storage containers, totes, or bins) containingvarious grocery products. The containers may be plastic, or any othersuitable material. Each grid area 114 b, 114 c can differ in height. Forexample, in the fulfilment centre illustrated in FIGS. 6 b and 6 c , thebulk of the ambient grid area comprises a 21 high container stack(approx. 7.7 m), and the chill grid area comprises an eight highcontainer stack (approx. 3.0 m), with a region of the grid above thepick station comprising a stack one container high (approx. 448 mm). Thecontainers are stacked on the floor on top of each other and fit betweenthe grid columns.

Each grid area comprises a tunnel 117 known as a pick aisle, whichhouses one or more pick stations for commodity items to be picked fromthe storage bins or containers and transferred to one or more deliverycontainers. FIG. 6 c shows a side view model of the chill grid area 114c showing the pick aisle 117 between two grid areas. Also shown in FIG.6 c is a separate area provided by incorporating a mezzanine supportedby vertical beams in amongst adjacent grid framework structures. Themezzanine can be a standalone structure. The mezzanine provides a tunnelto accommodate, for example, a pick station and/or any one of the abovedescribed stations.

Storage containers or bins storing commodity and grocery items aretransported by load handling devices operative on the grid to a pickstation in the pick aisle, where one or more items are picked from thestorage bin or container at the pick station and transferred to one ormore delivery containers. FIG. 6 d shows a perspective view of theupright columns being arranged to form vertical storage locations 58 forcontainers 10 to be stored within the vertical storage locations 58. Thebottom of FIG. 6 d shows a representation of the vertical stack up ofthe containers 10 between the upright columns 116.

Panelling 127 is used to limit and contain access into the gridframework structure for Health and Safety and operational reasons.Panelling 127 is attached directly to a building structure or tomezzanine columns or to panelling support columns 128. Different typesof panelling are used in different locations around the grid frameworkstructure, depending on different structural requirements. These includea trapezoidal panelling which is a corrugated metal sheet and usedthroughout the fulfilment centre to separate the grid areas fromwalkways (see FIG. 6 e ). The profile of the trapezoidal panelling shapeis shown at the bottom of FIG. 6 e . Panelling separating the pick aislein the chill area may be built of mesh to enable air circulation. Theupright columns 116 can be seen through the mesh panelling in FIG. 6 fPanelling support posts 128 and panels 127 are fixed along the mezzaninecolumns using appropriate beam clamps (see FIG. 60 . The panelling 127is attached to panelling support posts 128 as shown in FIG. 6 g . Thebottom of the panelling is secured to a kick plate (not shown) and thetop of the panelling is secured with a capping rail 125 as shown in FIG.6 g . The capping rail 125 is clearly shown in an expanded view to theright of FIG. 6 g.

Further detail of the components of the grid framework structure 114 isdiscussed below.

Upright Columns or Upright Members or Vertical Columns

FIG. 7 shows a cross-sectional top view of the upright columns 116 ofthe present invention arranged within the grid framework structure toprovide storage locations 58 (see FIG. 8 ) for containers 110 in a stackto be guided along the upright columns 116 and through a grid cell 54.The spacing between the upright columns is sized to accommodate one ormore containers or storage bins 110 which are generally rectangular in astack. Each of the upright columns are generally tubular. In transversecross-section in the horizontal plane of the storage location 58 in FIG.8 , each of the upright columns 116 comprises a hollow centre section 70with one or more guides 72 mounted to or formed to at least one wall ofthe upright column 116 that extends along the longitudinal length of theupright column 116 for guiding the movement of the containers. Thehollow centre section 70 of the upright columns aides to the low weightof the grid framework structure. In the particular embodiment shown inFIG. 7 , the hollow centre section 70 of the upright column is a boxsection. To at least one corner of the box section is mounted or formeda guide or corner section 72. However, there is no restriction to thecross-sectional shape of the hollow centre section of the upright columnbeing a box section as other shaped cross-sectional sections such ascircular, triangular, are applicable in the present invention.

The upright columns 116 are spaced apart as shown in FIG. 7 so that theguides 72 mounted to the corners of different box sections cooperatewith each other to provide a single storage location 58 for guiding themovement of containers vertically in a stack along the upright columns.Depending on the position of the upright columns 116 in the gridframework structure, guides 72 are mounted to one or all four corners ofthe box section of the upright column 116. For example, when formingpart of an exterior wall-shaped framework of the grid frameworkstructure only one or two of the corners of the hollow centre sectioncan comprise a guide or corner section 72 so as to cooperate with one ortwo corners of a container in a stack. In the case, where the uprightcolumn 116 is positioned within the interior of the grid frameworkstructure, all four corners of the box centre section comprises a guideor corner section 72, each of the upright columns 116 are arranged forcooperating with the corners of four containers 110.

In the particular embodiment of the present invention, each of theguides 72 are shown as V-shaped or has a 90° cross-sectional profilethat is shaped to butt up against or accommodate the profile of thecorners of the containers, which are generally rectangular in shape. Asshown in FIG. 7 , the guides comprises two perpendicular plates 72 a, 72b (two container guiding plates perpendicular to each other) that extendlongitudinally along the length of the upright column 116. An additionalplate 72 c shown in FIG. 7 extending along the length of the uprightcolumn is used to join the V-shaped guide at the apex of the V-shapedguide to the corner of the hollow centre section 70. The additionalplate 72 c is used to space the V-shaped guide away from the corner ofthe hollow centre section 70 so that the guide 72 including the spacer72 c has an overall Y-shaped cross-sectional profile.

The upright columns 116 of the present invention can be formed as asingle body, e.g. by means of extrusion. Different materials can be usedto fabricate the upright columns including but are not limited tometals, e.g. aluminium, steel or even composite materials that hassufficient structural rigidity to support the grid and the load bearingdevices traveling on the grid structure.

At least a portion of the plurality of the upright columns 116 are heldin space relation with each other in the grid framework structure by oneor more spacers or struts 74 connected between adjacent upright columns116 (see FIG. 8 ). The spacers 74 extend transversely to (orperpendicular to) the longitudinal direction of the upright column 116and are bolted or riveted to opposing walls of two adjacent uprightcolumns by one or more bolts or rivets. The length of the spacers orstruts 72 are sized such that adjacent upright columns 116 are spacedapart sufficiently to occupy one or more containers in a stack betweenthe upright columns 116. FIG. 8 shows a perspective view of four uprightcolumns 116 held in spaced apart relation with each other by one or morespacers or struts 74 to form a storage column or storage location 58that is sized to accommodate one or more containers in a stack.

The spacers 74 are sized to fit between the corner sections comprisingthe guides 72 of the upright column 116 so as to allow the uprightcolumns to accommodate a stack of containers between the adjacentupright columns 116, i.e. the spacers do not impede or cross the area(or vertical storage location) occupied by the guides 72 or guidingplates at the corners of the upright column (see FIG. 7 ). One or morespacers/struts 74 are distributed in spaced apart relation along thelength of two adjacent upright columns 116 in the grid frameworkstructure (see FIG. 8 ). FIG. 8 shows an example of a storage locationor storage column of the present invention for occupying one or morecontainers in a stack comprising four adjacent upright columns held inspaced apart relation within the grid framework structure by one or morespacers or struts 74.

It is essential that the level of the grid in the horizontal plane issubstantially flat for the load handling devices, which are largelyremotely operated, to travel on the grid structure and to prevent any ofthe tracks or rails being put under strain due to a variation in theheight of one or more of the upright members 116 in the grid frameworkstructure. To mitigate the possible height variation of one or more ofthe upright columns 116 in the grid framework structure, the height ofthe grid and thus, its level is adjusted by an adjustable foot 90 at alower end (first end) of one or more of the upright columns 90 (see FIG.8 ).

The adjustable foot 90 as shown in FIG. 9 comprises a base plate 92 anda threaded spindle or rod 94 that is threadingly engagable with aseparate push fit cap or plug 96 as shown in FIG. 10 . The push fit cap96 is arranged to be fitted to the lower end of the upright column 116in a tight fit so as to adjust the height of the upright column. Thepush fit cap 96 as shown in FIGS. 9 and 10 comprises an insert portion98 that is shaped to be inserted into the hollow centre section of theupright column. A lip 100 is formed around the periphery of the insertportion 98 that is arranged to butt up against the rim of the hollowcentre section 70 when the insert section 98 is received within thehollow centre section of the upright column. The push fit cap or plug 96comprises one or more compression clips or retaining clips 102 arrangedaround the insert portion 98 so as to form a tight fit when the insertportion 98 of the push fit cap or plug 96 is inserted into the hollowcentre section 70 of the upright column 116. In the particularembodiment of the present invention, the insert portion 98 is shaped toform a tight fit when inserted into the box section of the uprightcolumn. To create a tight fit between the insert portion 98 and thehollow centre section of the upright column 116, the insert portion 98comprises four walls 104 with one or more cut outs 106 in each of thewalls 104 to seat one or more of the retaining clips or compressionclips 102. The one or more retaining clips 102 can be composed of aresilient material, e.g. rubber. Together with the retaining clips 102,the insert portion 98 is slightly oversized than the hollow centresection 70 (which is a box section) of the upright column 116 so as toform a tight fit when the insert portion 98 is inserted into the boxsection 70 of the upright column 116. Another way of describing the pushfit cap or plug 96 comprises four corner sections, wherein each of thefour corner sections comprises two perpendicular strips or plates thatis arranged at a corner of a base plate of the push fit or plug 96.Spaces between the corner sections are sized to receive one or moreretaining clips 102.

The push fit cap 96 comprises a threaded hole 108 to threadingly engagewith the threaded spindle 94 of the adjustable foot 90. One or more webs115 extending from each apex of the corner sections to the threaded hole108 reinforce the structural integrity of the push fit cap 96. The pushfit cap 96 of the present invention can fabricated from metal or othersuitable material, e.g. metal, plastics, ceramic, and can be formed fromseparate parts, preferably formed as a single body, e.g. casting ormoulding.

In use, the threaded spindle 94 threadingly engages with the threadedhole 108 of the push fit cap 96. Rotation of the threaded spindle 94varies the distance between the base plate 92 resting on the floor andthe push fit cap 96 and thereby, varies the height of the upright columnin the grid framework structure.

Braced Tower

The grid framework structure 114 can be considered as a free standing(or self-supporting) rectilinear assemblage of a plurality uprightcolumns 116 supporting a grid formed from intersecting horizontal beamsor grid members, i.e. a four wall shaped framework. While the spacers orstruts 74 connecting adjacent upright columns 116 provide some degree ofstructural rigidity of the grid framework structure 114, structuralrigidity and moment resistance of the grid framework structure islargely provided by incorporating one or more truss assemblies or bracedtowers 80 at least partially around the periphery and/or within the bodyof the grid framework structure (see FIG. 6 a ). The truss assembly mayhave a triangular or other non-trapezoidal shape. For example, the trussassembly can be any type of truss that provides structural rigidity tothe grid framework structure against lateral forces including but arenot limited to Warren Truss or a K Truss or a Fink Truss or a PrattTruss or a Gambrel Truss or a Howe Truss. Bolts or other suitableattachment means may be used to secure the diagonal braces to theupright columns.

The braced tower 80 as shown in FIG. 11 according to an embodiment ofthe present invention can be formed by rigidly joining a sub-set orsub-group of the plurality of upright or vertical columns 116 by one ormore angled or diagonal braces or diagonal bracing members 82. For thepurpose of the present invention, the diagonal braces 82 cooperate withthe upright columns 116 in a braced tower 80 to form one or moretriangles. The sub-set of the plurality of upright columns that arebraced together to form the braced tower 80 of the present invention canbe two or more adjacent upright columns 116 lying in a same or in asingle vertical plane and joined together by one or more diagonal braces82. Putting it another way, two or more adjacent upright columns 116connected by one or more diagonal braces 82 lie in the same or singlevertical plane, i.e. they are co-planar. By bracing one or moresub-groups of the upright columns 116 internally within the gridframework structure by one or more diagonal braces 82, the structuralrigidity of the grid framework structure is improved.

Not all of the upright columns 116 are rigidly connected together by abracing assembly. The remaining upright columns that do not form part ofthe braced tower 80 are held in space relation within the grid frameworkstructure by one or more spacers or struts 74 as discussed above (seeFIG. 8 ). Typically, the one or more spacers 74 are fabricated fromsheet metal, e.g. steel. FIG. 12 shows a top plan view or a bird's eyeview of a portion of the grid framework structure showing thedistribution of the braced towers and the spacers linking adjacentupright columns 116 together according to one example of the presentinvention. Here, three braced towers 80 can each be shown as a sub-groupof three upright columns 116 a, 116 b, 116 c, each of the three bracedtowers lie in a single vertical plane, i.e. they are co-planar. Theremaining upright columns that are not connected by one or more diagonalbraces, are held in spaced apart relation in the grid frameworkstructure by one or more spacers or struts 74, 74 b. In comparison tothe one or more diagonal braces 82 connecting adjacent upright columns116 a, 116 b, 116 c in a braced tower 80, the spacers or struts 74, 74 bextend in a direction perpendicular to the longitudinal direction of theupright column 116. This can be clearly shown in the example of astorage column shown in FIG. 8 .

FIG. 12 shows the distribution of the spacers 74, 74 b separating theupright columns 116. FIG. 12 shows that there are two types of spacers74, 74 b connecting adjacent upright columns to the upright columns 116forming the braced tower 80. The upright columns 116 a, 116 b, 116 cforming the braced tower 80 are connected to one or more diagonal braces82. The spacer 74 b lying or extending in a vertical plane perpendicularto the vertical plane in which the upright columns of the braced tower80 lie are largely structural spacers 74 b and the spacers 74 extendinglaterally or to the side of the braced tower 80 to adjacent uprightcolumns 116 are largely a standard spacer 74. The two different types ofspacers 74, 74 b is dependent on whether one or more spacers are lyingin a plane perpendicular to the vertical plane in which the uprightcolumns 116 a, 116 b, 116 c of the braced towers 80 lie or lying in thesame vertical plane as the braced tower 80 (braced tower lie in a singleplane). In an example of the present invention, upright columns 116 a,116 b, 116 c forming the braced tower 80 can be connected to adjacentupright columns by one or more structural spacers or struts 74 b thatextend in the vertical plane perpendicular to the vertical plane inwhich the braced tower lie. Putting it another way, the upright columns116 a, 116 b, 116 c making up the braced tower 80 lie in a firstvertical plane and the structural spacers 74 b connecting the bracedtower 80 to adjacent upright columns 116 lie in a second vertical plane;the second vertical plane being perpendicular to the first verticalplane. A structural spacer 74 b is different to the spacer (standardspacer) 74 connecting the other remaining upright columns togetherwithin the grid framework structure in that it is more substantialcomprising one or more reinforcements to structurally support the spacer74 b. The reinforcements include but are not limited to the thickness orgauge of the sheet metal making up spacer or the inclusion of areinforcement beam. However, there is no restriction to the same type ofspacer that is used to space the upright columns 116 within the gridframework structure being used to connect the remaining upright columns116 adjacent the braced tower 80 of the present invention, i.e. theremaining upright columns that are not braced by one or more diagonalbraces are spaced apart by a standard spacer 74 throughout the gridframework structure.

The number of sub-groups of the upright columns rigidly connectedtogether by the brace assembly (one or more diagonal braces) within thegrid framework structure to form the braced tower 80 of the presentinvention and thus, the distribution of braced towers 80 is dependent ona number of factors including but is not limited to ground condition,e.g. soil condition, environmental factors such as temperature, and thelateral forces generated by the load handling devices. In a particularembodiment of the present invention, braced towers 80 are distributedwithin the grid framework structure to provide support from externalforces in the x and y direction. To do this, one or more of bracedtowers 80 are oriented within the grid framework structure 114 such thatone or more of the braced towers 80 lie in a first vertical plane andone or more braced towers lie in a second vertical plane, the firstvertical plane being perpendicular to the second vertical plane. Inanother example, the braced towers 80 can alternate amongst the uprightcolumns 116 within the body of the grid framework structure such thateach braced tower is adjacent to an equal number of upright columns 116.The braced towers 80 are separated from adjacent upright columns withinthe grid framework structure by one or more spacers or struts 74, 74 bas discussed above. In a given storage system comprising a gridframework structure, the number of upright columns occupied by thebraced tower (i.e. rigidly connected together one or more diagonalbraces) is in the region of 2% to 50% of the upright columns.

To maximise the available space or area for the storage of containers, asub-set or sub-group of adjacent upright columns 116 forming the bracedtower 80 and the one or more diagonal braces 82 connecting the sub-setof upright columns together all lie in the same or single verticalplane, i.e. they are co-planar. The one or more diagonal braces 82connecting the sub-set of adjacent upright columns 116 in a braced towerconstitute a bracing plane. In the braced tower of the presentinvention, the upright columns of the braced tower lie in a verticalplane that is parallel to the bracing plane. By bracing one or moreadjacent upright columns lying in a single vertical plane or which areco-planar, the ability of the upright columns being arranged toaccommodate a stack of containers is not compromised, i.e. increases thedensity of containers that can be stored in the grid frameworkstructure. In other words, the bracing members 82 do not cross a storagelocation in which containers are stacked nor does it impede with thecontainers being guided along adjacent upright columns.

In the particular embodiment of the present invention shown in FIG. 11 ,each of the braced towers 80 comprise three upright columns in parallelrelation and lie in a single vertical plane (co-planar) that are rigidlyconnected together by a plurality of diagonal braces 82. Two of thethree upright columns 116 a, 116 b are laterally disposed either side ofa middle upright column 116 c and the two laterally disposed uprightcolumn 116 a, 116 b are rigidly connected to the middle upright column116 c by a plurality of diagonal braces 82. Another way of describingthe braced tower 80 is two outer upright columns 116 a, 116 b eitherside of a middle upright column 116 c. In each of the braced towers 80,the outer upright columns 116 a, 116 b are joined together by one ormore cross bracing members with the middle upright column 116 b meetingat the intersection of a cross brace (more specifically, bracing members82 are used connect the outer upright column to the middle uprightcolumn 116 c either side of the middle upright column) as shown in FIG.11 .

In the braced tower 80 of the present invention, one end of a diagonalbracing member 82 is connected to the middle upright column by a joiningplate 130. The joining plate 130 is inserted into a slot through thehollow centre section of the middle upright column 116 c in a directionperpendicular to the longitudinal direction of the upright column. Asshown in the expanded view of the middle upright column in FIG. 14 , thejoining plate 130 is inserted through a slot in opposing walls of thehollow centre section 70 of the upright column.

Each of the diagonal bracing members 82 has a width that allows them tofit between two of the parallel guiding plates or guides at the cornerssections 72 of an upright column 116 and therefore, the diagonal braces82 does not compromise the ability of the upright column 116 toaccommodate a stack of containers. Putting it in a different way, thediagonal bracing members 82 do not intersect or cross an adjacent guideor guiding plates 72 at the corner of the upright column (see FIG. 7 ).To prevent the bracing members 82 impeding adjacent guide plates andthereby, compromise the area or storage location to accommodate a stackof containers, the slot for accommodating the joining plates 130 extendsbetween the guides 72 at the corners of the upright column 116 such thatwhen the bracing members 82 are connected to the joining plate 130, thebracing members 82 do not impede the guides 72 for guiding a containervertically along the upright columns 116.

Opposing ends of the joining plate 130 comprises one or more holes tofixedly attach to the end of the diagonal bracing members 82 by means ofsuitable bolts. Both ends of the joining plate 130 are fixedly attachedto the diagonal bracing members 82 either side of the middle uprightcolumn 116 c such that the joining plate 130 is put under tension in thebraced tower 80. A second end 82 b of the bracing members 82 is boltedto the outer upright column 116 a, 116 b by means of a flange plate 122fixedly attached to the outer upright column 116 a, 116 b (see FIG. 13)—a first end 82 a of the diagonal brace 82 is connected to the joiningplate 130. In the particular embodiment of the present invention shownin FIG. 13 , the flange 122 comprises a steel angle bolted 123 to theouter upright columns 116 a, 116 b. To ensure that the ends of thediagonal braces 82 are connected between the guides 72 and therefore, donot interrupt with one or more containers travelling along the guides,the flange 122 is fixedly attached between the guides 72 and enables thesecond end 82 a of the diagonal braces 82 to connect between the guides72.

To fix the diagonal bracing members 82 to the joining plate 130according to a first embodiment of the present invention shown in FIG.14 , the joining plate 130 comprises an insert plate 124 arranged to beinserted through the slot extending through the hollow centre section 70of the middle upright column 116 c. Bolted to either side of the insertplate 124 are wing plates 126 for connecting the bracing member 82 tothe joining plate 130. The use of multiple plates 124, 126 making up thejoining plate 130 allows for a smaller insert plate 124 to be used andthus, the wing plates 126 bolted to the insert plate 124 bears the loadapplied to the joining plate 130. However, the problem with the joiningplate 130 according to the first embodiment of the present inventionshown in FIG. 14 is that multiple bolts are need to rigidly connect thebracing member 82 to the middle upright column 116 c. In the particularembodiment of the present invention shown in FIG. 14 , each of the wingplates 126 is bolted to the insert plate 124 by four bolts. Anadditional two bolts are used to connect the ends (second end) of thebracing member 82 to the top and bottom of each of the wing plates 126.

In an improved version of the joining plate 130 according to a secondembodiment of the present invention as shown in FIG. 15 is shown as asingle joining plate 130 as opposed to multiple joined plates. Theinsert plate and the wing plate are fabricated as a single joining plate130 that is sized to be inserted into a slot in the middle uprightcolumn 116 c. The removal of the separate wing plates removes the needto bolt separate wings plate to the insert plate and thereby, removesthe need to have multiple bolts to connect the diagonal bracing members82 to the middle upright column 116 c. In the particular embodiment ofthe present invention, a single joining plate 130 is inserted into aslot extending in the hollow central portion of the middle uprightcolumn 116 c. Bracing members 82 are bolted to each corner of thejoining plate 130. To accommodate the joining plate 130 according to asecond embodiment of the present invention without affecting thestructural integrity of the upright column and without affecting thestorage location for accommodating a stack of containers betweenadjacent upright columns, the hollow centre section of each uprightcolumn can be made larger, i.e. the cross sectional area of the hollowcentre section 70 is made bigger. In the case, where the hollow centresection of the upright column is a box section comprising four walls,the width of the walls are increased to provide a larger box section 70to accommodate the joining plate 130 without impeding on the guides 72at the corners of the box section 70.

Multiple joining plates 130 are spaced apart along the longitudinallength of the middle upright column 116 c so that the diagonal bracingmembers 82 connected between the outer upright columns 116 a, 116 b andthe middle upright column 116 c form a series of triangular braceseither side of the middle upright column 116 c. The bracing memberseither side of the middle upright column 116 c work together with theouter upright column 116 a, 116 b to provide a unitary truss assembly orbraced tower 80 having a cross-brace.

Braced Tower Foot

One or more braced towers 80 are anchored to a concrete foundation. Thebraced towers 80 function to transfer the lateral forces experienced bythe grid 50 to the floor. The braced towers 80 are anchored to theconcrete foundation by one or more anchor feet 132 (see FIGS. 11 and 15). In the particular embodiment shown in FIG. 11 and FIG. 15 , the outerupright columns 116 a, 116 b or the laterally disposed upright columns116 a, 116 b are anchored to the concrete foundation by one or moreanchor feet 132 and the middle upright column 116 c is supported on anadjustable foot 90 as discussed above. The lower end (first end) of thebraced tower is anchored to the concrete foundation by one or moreanchor bolts. Various types of anchor feet 132 a, 132 b to rigidlyanchor the braced tower to the concrete foundation is applicable in thepresent invention. The anchor foot functions to bear the upright columnload and the bracing load of the bracing assembly 82 of the braced tower80.

FIGS. 11(c) and 16 show two examples of the anchor foot that is used toanchor the braced tower to the concrete foundation according to thepresent invention. In comparison to the anchor foot shown in FIG. 16 ,the anchor foot shown in FIG. 11(c) is more substantial in terms of sizeand weight in comparison to the anchor foot shown in FIG. 16 . Theanchor foot 132 a shown in FIG. 11(c) is fabricated as a T-jointcomprising a base plate 133 lying in a horizontal plane for anchoring tothe floor by one or more anchor bolts and an anchor plate 134perpendicular to the base plate 133 for attaching to the lower end ofthe upright column and the ends of the bracing member 82. The anchorplate 134 is orientated such that the surface of the anchor plate 134with the greatest surface area lies in the same vertical plane as thethree upright columns 116 a, 116 b, 116 c of the braced tower 80, e.g.the surface of the anchor plate 134 with the greatest surface area andthe upright members 116 a, 116 b, 116 c of the braced tower 80 areco-planar. The problem with the anchor foot 132 a shown in FIG. 11(c) isthe substantial weight and thus, cost to fabricate the anchor foot.

FIG. 16 shows an alternative anchor foot 132 b for anchoring the bracedtower 80 to the concrete foundation according to second embodiment ofthe present invention. Instead of a solid rectangular base plate 133,the anchor foot is topology optimised that optimizes the materialslayout within a given design space for a given set of loads. Two loadsconsidered in the topology optimisation of the anchor foot are the loadsfrom the upright columns 116 a, 116 b, 116 c and the bracing members 82.Based on the constraints given by the applied loads, the anchor foot 132b of the present invention comprises a stabiliser 136 comprising aplurality of discrete fingers or digits 138 extending from an uprightportion 140 such that loads are distributed amongst the plurality offingers 138, e.g. separate fingers. In the particular embodiment of thepresent invention shown in FIG. 16 , the upright portion 140 comprisesan anchor plate arranged to rigidly connect to the upright column 116 a,116 b and the diagonal brace 82 by one or more bolts so as to bear theload of the upright column 116 a, 116 b and the applied load of thediagonal brace 82. Like the anchor plate 134 of the first embodiment ofthe present invention shown in FIG. 11(c), the anchor plate 140 isoriented such that the surface of the anchor plate 140 with the greatestsurface area lies in the same vertical plate as the three uprightcolumns 116 a, 116 b, 116 c making up the braced tower 80 of the presentinvention (see FIG. 11 ). Using the terminology of the presentinvention, the upright columns 116 a, 116 b, 116 c, the diagonal braces82 and the surface of the anchor plate 134, 140 all lie in the sameplane, i.e. they are co-planar.

One or more of the discrete fingers 138 of the anchor foot 132 b extendor span out or extend outwardly in two or more different directions fromthe upright portion 140 so as to provide improved stability of theanchor foot 132 b. One or more of the fingers 138 are of differentlengths to aid with the stability of the anchor foot 132 b of thepresent invention. The length of the fingers 138 can be different soprovide different levels of stability of the braced tower 80. One ormore connecting webs 142 are used to support the one or more of thefingers 138 from axial movement. The anchor foot 132 b is anchored tothe concrete foundation by one or more bolts through holes in thefingers 138 of the anchor foot 132 b.

In the particular embodiment of the present invention, five fingers 138of varying length are shown (see FIG. 16 b ) that extend from theupright portion 140 with holes at the distal ends of the fingers 138 foranchoring the anchor foot to the ground via an anchor bolt. The anchorfoot 132 b according to the second embodiment of the present inventioncan be formed as a single body, e.g. casting, or separate parts joinedtogether, e.g. welding.

Grid Structure

Mounted to the upright columns 116 is a grid 50 comprising a pluralityof grid members 118, 120 arranged to form a grid pattern comprising oneor more rectangular frames each of the rectangular frames constituting agrid cell 54 that are positioned above a storage location for one ormore containers in a stack to be retrieved by a load handling deviceoperative on the grid. The grid comprises a first set of parallel gridmembers 118 extending in a first direction x and a second set ofparallel grid members 120 extending in a second direction y. The secondset of grid members 118 is perpendicular to the first set of gridmembers 120 in a substantially horizontal plane to form a grid structurecomprising a plurality of grid cells 54. As the grid lies in thehorizontal plane, the first and the second direction are in the X axialdirection and in the Y axial direction respectively (see FIG. 17 ). Theplurality of upright columns are interconnected at their top ends by thefirst set of grid members 118 extending in the first direction and thesecond set of grid members 120 extending in the second direction.Further details of the interconnection between the grid members at thetop end of the upright columns is discussed below. FIG. 17 shows a topview of a grid structure 50 according to an embodiment of the presentinvention.

Each of the grid members 118, 120 comprises a track support to which ismounted a track. The track can be a separate component to the gridmember or alternatively, the track support is integrated into the gridmember as a single body, i.e. forms part of the grid member. The loadhandling device is operative to move along the track of the grid. Thegrid is supported by a plurality of the upright columns at each of theintersections of the horizontal grid members 118, 120. The term‘intersections’ is construed in the broadest sense to cover the junctionwhere the grid members cross at an upper end of an upright column or theends of the grid members 118, 10 meet at the upright columns. For thepurpose of explanation, the lower end of the upright column mounted tothe floor constitutes the first end of the upright column and the upperend of the upright column adjacent the grid 50 constitutes the secondend of the upright column.

The sets of parallel grid members 118, 120 can be sub-divided intosubsets of grid members extending in the first (118 a, 118 b) and/orsecond direction (120 a, 120 b) of the grid framework structure. Asubset can constitute at least one grid member extending in either firstdirection or the second direction in a set, e.g. a single grid member.At least one grid member in a subset, e.g. a single grid member, can besub-divided or sectioned into discrete grid elements (119 a, 119 b, 119c etc and 121 a, 121 b, 121 c etc) that can be joined or linked togetherto form a grid member 118, 120 extending in the first direction or inthe second direction. The discrete grid elements 119, 121 making up thegrid extending in the first axial direction (119) and in the secondaxial direction (121) are shown in FIG. 17 .

A connection plate or cap plate 150 as shown in FIG. 18 can be used tolink or join the individual grid elements (119 a, 119 b, 119 c etc and121 a, 121 b, 121 c etc) together in a subset in both the first and thesecond direction at the junction where multiple grid elements cross inthe grid structure, i.e. the cap plate 150 is used to connect the gridelements together to the upright columns 116. As a result, the uprightcolumns are interconnected at their upper ends at the junction where themultiple grid elements cross in the grid structure by the cap plate 150.As shown in FIG. 18 , the cap plate 150 is cross shaped having fourconnecting portions 152 for connecting to the ends or anywhere along thelength of the grid elements 119, 121 at their intersections (see FIGS.19 and 20 ). For example, the cap plate 150 can be used to connect tothe ends of four grid elements 119, 121 as shown in FIG. 19 . In FIG. 19, the ends of two grid elements 119 a, 119 b are connected to the capplate 150. Alternatively, the cap plate 150 can used to connect to threegrid elements by connecting to a point anywhere along the length of onegrid element 121 and the ends of two other adjacent grid elements 119 a,119 b as shown in FIG. 20 . The cap plate 150 comprises a spigot orprotrusion 154 that is sized to sit in the hollow central section 70 ofthe upright column 116 (at the second end of the upright column) in atight fit for interconnecting the plurality of upright columns to thegrid members as shown in FIG. 21 . The connecting portions 154 areperpendicular to each other to connect to the grid members 118, 120/gridelements 119, 121 extending in the first direction and in the seconddirection. The cap plate is configured to be bolted to the ends of thegrid elements or along the length of the grid elements. However, the capplate does not necessarily need to be cross shaped as the number ofconnecting portions of the cap plate can be dependent on whether the capplate is positioned at the corner of the grid framework structure or atone of the walls of the grid framework structure. For the purpose ofexplanation of the present invention, the intersections where the gridmembers cross at the upright columns constitute the nodes of the grid.Bending moments of the grid are concentrated at the nodes of the grid.

Various pattern arrangements of the grid members 118, 120 can be used togenerate the grid 50 of the present invention. For example, the gridmembers in a sub-set can be sub-divided into multiple discretegrid-elements 119 a, 119 b in the first direction and multiple discretegrid-elements 121 a, 121 b in the second direction. Each of the multiplegrid elements can be bolted to the cap plate 150 at their respectiveends in the first direction and in the second direction (X- andY-direction), i.e. the grid elements are joined by their ends in thegrid by the cap plates in the first direction and the second direction.Thus, the length of each of the grid elements in both axial directionsare sized to lie between two adjacent upright columns 116.

The problem with this arrangement is that the grid would requiremultiple cuts of the grid elements to connect to each of the uprightcolumns in the grid framework structure. As a result, lateral forcesexperienced by the grid are concentrated at the joints or nodes betweenthe ends of the grid elements and the cap plate 150. Such an arrangementdoes not provide the best overall distribution of the lateral forces andstructural integrity of the grid. An alternative arrangement to improvestructural rigidity of the grid would be to have different lengths ofthe grid elements 119, 121 along either the first direction or thesecond direction or both. For example, two or more of the grid elementsare sized to extend or span over one or more upright columns 116 in thefirst direction and connected to the cap plate 150 anywhere along thelength of the grid element. In the second direction perpendicular to thefirst direction, the ends of the grid elements are connected to the capplate. Whilst this arrangement may be beneficial in terms of improvingthe structural integrity of the grid, this may not be consideredeconomical as multiple cuts of the grid members are necessary. Also, theneed to assemble and connect different lengths of the grid elements tothe upright columns adds to the complexity of assembling the grid.

The present applicant has realised that arranging the grid elements ofthe grid members to create a pattern having a woven-like appearance orbrick like appearance so that adjacent parallel grid elements in thefirst direction are offset by at least one grid cell 54 as shown in FIG.17 improves both the structural integrity of the grid as well as be ableto use the same length grid elements in either the first direction andthe second direction. Similarly, adjacent parallel grid elements arearranged in the second direction so as to be offset by at least one gridcell 54. In an exploded view of the grid pattern shown in FIG. 22 ,adjacent parallel grid elements (119 a and 119 b; 121 a and 121 b) arearranged in the grid so that the adjacent parallel grid elements in thefirst direction and the second direction are offset by a single gridcell 54. For example, in FIG. 22 , grid element 119 a is offset fromgrid element 119 b in the first direction by a single grid cell 54.Similarly, grid element 121 a is offset from grid element 121 b in thesecond direction by a single grid cell 54. Such a woven-like appearanceis termed a lamellar pattern according to the terminology used in thepresent invention. In this arrangement of the grid, the same size gridelements can be used throughout most of the grid structure—much like thesame size bricks are used to create a brick-like appearance where thebricks are arranged in a staggered arrangement. As can be made apparentin FIG. 17 , the pattern of grid elements are arranged so that adjacentgrid elements in the first direction and in the second directioninterdigitate.

To achieve this pattern, the length of one or more of the grid elements119, 121 of a grid member 118, 120 are sized to extend or span acrossthe upper ends of one or more upright columns in the first directionand/or in the second direction as opposed to all being sized to connectby its ends to the upright columns in the grid framework structure. As aresult of this arrangement, one or more of the grid elements in thefirst direction 119 and in the second direction 121 are secured to theupright column via the cap plate 150 at various positions along thelength of the grid. In the particular embodiment of the presentinvention as shown in FIG. 20 , the length of each of the grid elementsare sized to extend or span a single upright column.

As a result of this pattern arrangement, the upper end of an uprightcolumn 116 is connected to a first grid element 121 half way along itslength in the first direction, and in the second direction the ends oftwo other adjacent grid elements 119 a, 119 b either side of the firstgrid element 121 (see FIG. 20 ), i.e. the upper end of the uprightcolumns in the grid framework structure are interconnected by supportingan end of a grid element 119 and a centre of adjacent grid element 121.Sub-dividing a sub-set of grid members in the first direction and thesecond direction into a plurality of grid elements, and staggering thegrid elements 119 a, 119 b, 119 c, 121 a, 121 b, 121 c in the firstdirection and in the second direction such that each of the gridelements extend or span a single upright column 116 results in anarrangement where the grid elements in the first direction and in thesecond direction are offset by at least one grid cell 54. Morespecifically, a first subset of grid members 118, 120 are sub-dividedinto a first and second grid elements extending in the first direction119 a, 119 b, the second grid element 119 b being spaced apart in thesecond direction from the first grid element 119 a. The first and secondgrid elements 119 a, 119 b are staggered in the first direction suchthat the first grid element 119 a and the second grid element 119 b inthe grid are offset by at least one grid cell 54. The same staggeredarrangement of the grid elements apply in the second direction, wherebythe first and second grid elements in the second direction 121 a, 121 bthat are spaced apart in the first direction are offset in the seconddirection by at least one grid cell.

The present invention is not restricted to the first and the second gridelements being staggered in the first direction and/or the seconddirection being offset by a single grid cell. For example, one or moreof the grid elements in the first direction and/or the second directioncan be sized to span or extend across the upper ends of multiple uprightcolumns and the staggered arrangement creates a pattern that is offsetin the first direction and/or the second direction by one or more gridcells. Such an arrangement requires multiple connections along thelength of the grid element with multiple upright columns rather thanjust in the middle of the grid element. The connection the grid membersto the upright columns, particularly the cross-sectional shape of thegrid elements is further discussed below.

The containers are generally rectangular in shape having a length longerthan its width. The grid cells are rectangular to accommodaterectangular shaped containers. To achieve rectangular grid cells, thelength of each of the grid elements 119 in the first axial direction (xor y direction) is longer than the length of each of the grid elements121 in the second axial direction (y or x direction). The preferred gridarrangement shown in FIG. 17 and FIG. 22 provides optimal structuralintegrity of grid 50 of the present invention. In this arrangement, asubset of grid members 118, 120 are sub-divided into grid elements 119,121 that extend across at least one upright column 116 in both the firstand the second direction. In a more preferred embodiment of the presentinvention, the grid members are sub-divided so that each of the gridelements extend across a single upright column in both the first andsecond axial directions. In this arrangement, the length of each of thegrid elements is the same in the first direction and the length of eachof the grid elements is the same in the second direction but aredifferent in both the first and second direction to provide arectangular shaped grid cell. In other words and making reference toFIGS. 17 and 22 , the subset of the grid members 119 in the firstdirection are sub-divided into a first grid element 119 a and a secondgrid element 119 b, each of the first grid element 119 a and the secondgrid element 119 b in the first direction has a length L1 (see FIG. 22). Similarly, the subset of grid members in the second direction 120 aresub-divided into a first grid element 121 a and a second grid element121 b, each of the first grid element 121 a and the second grid element121 b in the second direction has a length L2. To accommodate therectangular containers, the length L1 of the grid elements in the firstdirection is different to the length L2 of the grid elements in thesecond direction.

Different portions of the grid can be arranged to have the lamellarpattern. To give the grid sufficient structural rigidity to support themoving load bearing devices, a greater proportion of the grid adopts thelamellar pattern of the present invention. For example, due to the gridelements being arranged to be offset by at least one grid cell in thefirst direction and the second direction, one or more of the gridelements at the periphery of the grid are cut short so as to meet at acommon support beam. This is to prevent one or more grid elementsoverhanging at the edge of the grid structure, i.e. one or more gridelements over hanging a common support beam at the edge of the grid arecut.

Track Support

Each of the grid members 50 of the present invention can comprise atrack support and/or a track or rail whereby the track or rail ismounted to the track support. The load handling device is operative tomove along the track or rail of the present invention. Alternatively,the track can be integrated into the grid member 50 as a single body,e.g. by extrusion.

In the particular embodiment of the present invention, the grid memberis the track support to which is mounted a separate track or rail, i.e.the track support is integrated into the grid member. The track supportmaking up the grid in transverse cross section can be a solid support ofC-shaped or U-shaped or I shaped cross section or even double C ordouble U shaped support. In the particular embodiment of the presentinvention, the track support is a double back-to-back C sections boltedtogether. The track support and/or the track can adopt a similarlamellar pattern discussed above with respect to the grid members. Thetrack support is sub-divided into track support elements that are joinedtogether in the first direction and in the second direction at thejunction where the multiple track support elements cross in the gridstructure, i.e. at the upper end of the upright column.

Using the same terminology above with respect of the grid members (seeFIGS. 17 and 22 ), the grid comprises a first set of parallel tracksupports extending in the first direction and a second set of paralleltrack supports extending in the second direction, the second set oftrack supports is substantially perpendicular to the first set of tracksupports. In each of the first direction and in the second direction,the set of track supports comprises multiple parallel track supports.Like the sub-sets of grid members discussed above, the first set oftrack supports in the first direction is sub-divided in the firstdirection into a first sub-set of track supports and a second sub-set oftrack supports such that the second subset of track supports is spacedapart from the first sub-set of the track supports in the seconddirection, i.e., parallel sub-sets of track supports. The first sub-setof track supports and/or the second sub-set of tracks supports comprisesat least one track support, e.g. a single track support. The firstsubset of track supports is sub-divided or broken down in the firstdirection into first track support elements. A second subset of tracksupports adjacent to the first subset of track supports is similarlysub-divided in the first direction into second track support elements.The first and second track support elements are arranged in the grid sothat each of the first track support elements is offset from each ofadjacent second set of track support elements in the first direction byat least one single grid cell, i.e. adjacent parallel track supportelements are offset by at least one grid cell in the first direction.For example, a subset of the track supports comprising a single tracksupport is broken down into multiple discrete track support elementsthat are joined together via the cap plates to form a single tracksupport. Parallel discrete track support elements in the first directionare arranged in the grid to be offset by at least one grid cell. Asimilar pattern arrangement applies to the set of track supportsextending in the second direction whereby the set of track supports aresub-divided in the second direction into a first sub-set and secondsub-set of track supports. Each of the first and second sub-set of tracksupport are broken down or divided into first and second track supportelements. The first and second track support elements extending in thesecond direction are arranged in the grid so that each of the firsttrack support elements is offset from each of the second track supportelements in the second direction by at least one single grid cell.Putting it another way, laterally disposed parallel track elements inthe first direction and in the second direction are offset by at leastone grid cell.

An individual track support element 160 comprises back to back Csections that are bolted together according to an embodiment of thepresent invention is shown in FIG. 23 . FIG. 24 shows a cross section ofthe grid elements 160 along the line X-X in FIG. 20 at the intersection.Each of the track support elements 160 are arranged to interlock witheach other to from the grid according to the present invention. Toachieve this, distal or opposing ends of each of the track supportelements 160 comprises locking features 162 for interconnecting tocorresponding locking features 164 of adjacent track support elements.In the particular embodiment of the present invention, opposing ordistal ends of one or more track support elements comprises at least onehook 162 that is receivable in openings or slot 164 midway of anadjacent grid element at the junction where the track support elementscross in the grid. Referring back to FIG. 23 in combination with FIG. 24, the hooks 162 at the end of a track support element 160 are shownreceived in an opening 164 of an adjacent track support elementextending across an upright column at the junction where the tracksupport elements cross. Here, the hooks 162 are offered up to an opening164 either side of a track support element. In the particular embodimentof the present invention, the opening 164 is half way along the lengthof the track support element 160 so that when assembled together,adjacent parallel track support elements in the first direction and inthe second direction are offset by at least one grid cell. Withreference to FIG. 20 and FIG. 24 the upright columns supports 116 thecentre of a first track support element 160 a and the ends of adjacentsecond 160 b and third 160 c track support elements either side of thefirst track support element 160 a, i.e. each of the upright columns 116supports three track support elements 160 a, 160 b, 160 c. The secondand third track support elements 160 b, 160 c, supported at their endsare approached in opposite directions to interlock mid-way along thefirst track support element 160 a. Each of the track support elements160 a, 160 b, 160 c are interlocked by inserting the hooks 162 at theends of the track support elements into openings 164 mid-way of anadjacent track support elements at the junction where the track supportelements cross. By interlocking each of the track support elements inthe grid through this manner the lamellar pattern as described aboveresults.

Track or Rail

To complete the grid structure once the track support elements areinterlocked together to form a grid pattern comprising track supportsextending in the first direction and track supports extending in thesecond direction, a track is mounted to the track support elements. Thetrack is either snap-fitted and/or fitted to the track support elementsin a slid fit arrangement. Like the track support of the presentinvention, the track comprises a first set of tracks extending in thefirst direction and a second set of tracks extending in the seconddirection, the first direction being perpendicular to the seconddirection. A sub-set of the first set of tracks is sub-divided intomultiple track elements in the first direction such that adjacentparallel track elements in the first direction are offset by at leastonce grid cell. Similarly, a sub-set of the second set of tracks issub-divided into multiple track elements in the second direction suchthat adjacent track elements in the second direction are offset by atleast one grid cell. A sub-set of the first set and/or the second set oftracks comprises at least one track, e.g. a single track that is brokendown into multiple track elements. An example of a single track element170 is shown in FIG. 25 . The fitting of the track element to the tracksupport comprises an inverted U-shaped cross-sectional profile that isshaped to cradle or overlap the top of the track support element 160shown in FIG. 23 . One or more lugs extending from each branch of the Ushape profile engage with the ends of the track support in a snap fitarrangement.

Multiple track elements 170 are assembled to butt up against each otheralong the length of the track support elements. Individual tracks canfollow a similar pattern to the track supports, e.g. lamellar pattern,or arranged in a different arrangement. FIG. 26 shows an assembly ofthree track elements 170 a, 170 b, 170 c at a junction where the trackelements 170 a, 170 b, 170 c cross in the grid structure at an uprightcolumn. The length of each of the track elements are sized to extend orspan across at least one upright column, e.g. a single upright column.The ends of the track elements 170 a, 170 b butt up against the side ofan adjacent track element 170 c at an upright column. The track elements170 comprises a cut out or recess 172 as shown in FIG. 25 to accommodatethe track support elements 160 at an upright column discussed above.Since the track elements 170 are sized to extend or span across a singleupright in the grid structure, the cut out 172 is at the centre orformed midway of each of the track elements 170. The track elements 170are assembled on the track support such that the track has a woven likeor brick like appearance as viewed from the top of the grid, whereinadjacent parallel track elements in the first direction are staggered byat least one grid cell. Similarly, adjacent parallel track elements inthe second direction are staggered by at least one grid cell.

Using the similar language discussed above with reference to the gridmembers. The track comprises a first set of tracks extending in a firstdirection and a second set of tracks extending in the second direction,the second set of tracks running transversely to the first set of tracksin a substantially horizontal plane. The first and the second sets oftracks are sub-divided into a plurality of track elements 170 such thateach of the plurality of track elements 170 are arranged to extends orspan across the top end of a single upright member. More specifically,the first set of tracks is sub-divided in the first direction into afirst subset of tracks and a second subset of tracks extending in thefirst direction, the second subset of tracks is spaced apart from thefirst subset of the tracks in the second direction. The first subset oftracks is broken down or divided in the first direction into a first setof tracks elements 170 and the second subset of tracks is broken down ordivided in the first direction into a second set of tracks elements. Thefirst set of tracks elements is offset from the second set of trackselements in the first direction by single grid cell. The same principleapplies to a first set of track elements and a second set of trackselements extending in the second direction.

The upright columns, braced tower, braced tower foot, grid structurecomprising the track support and the track elements are assembledtogether as described above to form the grid framework structureaccording to an embodiment of the present invention.

Seismic Grid Framework Structure

While the current grid framework structure is adequate where the groundis relatively stable, i.e. having a spectral acceleration less than 0.33g categorised as Type A and Type B events, this cannot be said where thegrid framework structure is subjected to powerful seismic eventsgenerating strong lateral forces in excess of 0.55 g spectralacceleration categorised as a Type C or D seismic event. Such powerfulseismic events compromise the structural fasteners joining the gridelements (e.g. track support elements) at the intersections, causingthem to work their way loose or out of the cap plates to which they arebolted to. The result is the weakening or complete loss of structuralintegrity of the grid framework structure as the lateral forces nolonger are able to be transferred safely down to the structuralfoundations. Failure may occur at the intersections of the grid membersor track support elements making up the grid. The bracing towersdescribed above used to maintain the structural integrity of the gridframework structure may not able to withstand the lateral forces as aresult of powerful Type D seismic events well in excess of 0.55 g.

The present invention as shown in FIGS. 27 and 28 provides a seismicrestraint grid framework structure 214 and 314 comprising a structuralrestraint system otherwise known as a seismic force restraint system(SFRS) to maintain the structural integrity of the grid frameworkstructure of the present invention during powerful seismic and stormevents, i.e. the SFRS supports the grid framework structure of thepresent invention against strong lateral forces as a result of Type Cand/or D seismic events. The restraint system of the present inventionreduces or eliminates structural fastener failure such as the jointssecuring the grid elements to the upright columns via the cap plates atthe intersections through breakage, loosening, detachment or rupturethrough structural components. The SFRS of the present inventioncomprises a perimeter bracing structure 215, 315 supported by aplurality of vertical frame columns 218, 318 for supporting the gridagainst lateral forces. The reference numerals 215 and 315 are used todescribe the different types of perimeter bracing structure shown inFIG. 27 and FIG. 28 . The perimeter bracing structure 215, 315 comprisesat least one bracing member 220, 320, 222, 322 extending from theplurality of vertical frame columns 218. For the purpose of the presentinvention, the term “support” is construed to cover any form ofmechanical connection between the SFRS and the grid. For example,lateral forces generated at the grid level are transferred at theperiphery of the grid 250 to the SFRS of the present invention.Additionally, for the purpose of the present invention, the at least onebracing member 220, 320, 222, 322 can be at least one horizontal framebeam between the vertical frame columns 218 and/or at least one diagonalbracing member 222, 322 between the vertical frame columns 218. For thepurpose of the present invention, the term “vertical frame column” and“vertical support frame column” are used interchangeably in thedescription to represent the columns 218 supporting the bracing members220, 320, 222, 322. A vertical frame column 218 is different to thevertical upright columns 116 supporting the grid discussed above and arespaced apart by one or more spacers 74. The vertical frame column 218forms part of the SFRS together with the perimeter bracing structure ofthe present invention. The SFRS can be envisaged to form an exoskeletonaround the grid framework structure.

The grid 250 comprises an outer zone or border 252 around the peripheryof the grid 250 (see FIG. 29 ). FIG. 29 shows an expanded view of theseismic restraint grid framework structure of the present invention atone of the corners of the SFRS 215, 315 supporting the grid frameworkstructure. The grid 250 is supported by the perimeter bracing structure215, 315 at or within the border or outer zone 252 of the grid 250. Inone embodiment of the present invention, the perimeter bracing structure215, 315 is arranged around the periphery of the grid 250 and/or thegrid framework structure. In a preferred embodiment of the presentinvention, the grid 250 is supported by the perimeter bracing structure215, 315 at or within the border or outer zone 252 of the grid 250 suchthat a portion of the border or outer zone 252 overhangs the perimeterbracing structure 215, 315. In the particular embodiment of the presentinvention, the border or outer zone 252 of the grid 250 constitutes anouter portion of the grid 250 having a width of at least one grid cell,more preferably a single grid cell such that the outer portion of thegrid 250 overhangs the perimeter bracing structure 215, 315 when thegrid 250 is supported at the borders or outer zone 252 of the grid 250.

As shown in FIG. 29 , the outer zone or border 252 of the grid spans orextends across the perimeter bracing structure 215, 315 at the edges ofthe grid framework structure. More specifically, the outer zone orborder 252 of the grid spans across the at least one bracing member 220such that a portion of the grid overhangs the perimeter bracingstructure 215, 315. The at least one bracing member 220 is the at leastone horizontal frame beam extending between the vertical frame columns218. Here, the at least one horizontal frame beam 220 is inwardlypositioned from the edge of the grid 250 such that the outer zone orborder 252 of the grid spans or extends across the at least onehorizontal frame beam 220.

By supporting the grid 250 at the border or outer zone 252 of the gridsuch that a portion of the grid 250 overhangs the perimeter bracingstructure 215, 315 rather than being supported at the edge of the gridmitigates the bending moments at the edge of the grid affecting thejoints connecting the grid 250 to the perimeter bracing structure 215,315 of the present invention. This is because the bending moments isgreatest at the edges of the grid 250 where the grid members intersectand decreases between the intersections, i.e. within the grid cells ormid-cell. This is further explained below with reference to FIG. 33showing the distribution of the bending moments across the grid. In FIG.33 , it can be seen that the bending moments is maximum at the edge ofthe grid where the grid elements intersect and decreases to a minimumbetween the intersections. In the particular embodiment of the presentinvention shown in FIG. 29 , the width D of the border or outer zone 252around the grid constitutes a single grid cell. Ideally, the grid 250 issupported mid-cell within the border or outer zone 252 of the grid 250by the at least one bracing member 220 of the perimeter bracingstructure 215, 315 where the bending moments is the weakest rather thanat the edges of the grid 250.

Whilst it is ideal to support the grid 250 mid-cell at the border orouter zone of the grid, the present invention is not limited to the gridbeing supported mid-cell at the border or the outer zone of the grid andthe border or outer zone of the grid can be construed to also constitutethe edges of the grid 250 such that the grid 250 is supported around theperipheral of the grid by the perimeter bracing structure of the presentinvention.

The SFRS can be imagined to form an exoskeleton around the gridframework structure of the present invention. In the particularembodiment of the present invention, the perimeter bracing structure215, 315 is supported by at least one vertical frame column 218 a at thecorners of the grid framework structure and braced by at least onehorizontal frame beam 220 extending from the corners of the gridframework structure. In the particular embodiment of the presentinvention as shown in FIG. 27 and FIG. 28 , four vertical framesupporting columns 218 a are arranged at four corners of the gridframework structure to form a 3 dimensional exoskeleton, e.g. cuboidstructure, having a top face and four side faces. As the SFRS forms anexoskeleton around the periphery of the grid framework structure of thepresent invention, the vertical frame support columns 218 a at thecorners of the grid framework structure can be termed perimeter framecolumns for ease of explanation of the SFRS of the present invention. Inthe particular embodiment of the present invention, four horizontalframe beams 220 are mounted to the top of each of the four perimeterframe columns 218 a so as to extend from each corner of the SFRS frame.The horizontal frame beams 220 can envisaged to represent the top chordsthat connects two vertical frames columns 218 a at their top ends of theperimeter bracing structure 215, 315 and can be termed a perimeter framebeam.

At least two of the vertical frame columns 218 a, 218 b are joinedtogether by at least one diagonal bracing member 222, 322 to form abraced frame to provide lateral support for the grid framework structurein the front and/or the back direction. The braced frame is a structuralsystem which is designed to resist earthquake forces. The diagonalbracing members 222, 322 are designed to work in tension andcompression, similar to a truss and are designed to resist lateral loadsin the form of axial stresses, by either tension or compression. Abraced frame can be arranged around the periphery of the grid frameworkstructure or at least one face of the grid framework structure anddesigned to absorb the bulk of the lateral forces experienced by thegrid framework structure.

Any type of braced frame commonly known in the art to provide lateralsupport to the grid and/or grid framework structure is applicable in thepresent invention. In the particular embodiment of the present inventionshown in FIGS. 27 and 28 , the braced frame can be a K-brace where twodiagonal braces 222 meet at a peak 324 on the horizontal frame beam 320as shown in FIG. 28 or a cross-brace where two diagonal braces 222 crosseach other to form an X as shown in FIG. 27 . Further detail of theK-brace and the cross brace is discussed below. Bracing at least two ofthe vertical frame columns 218 a, 218 b at the top of the vertical framecolumns 218 a, 218 b by at least one horizontal frame beam 220, 320forms at least one drag strut or collector commonly known in the art. Adrag strut or collector is where the at least two vertical frame columns218 a, 218 b are braced by the horizontal frame beams 220, 320 at thetop of the two vertical frame columns 218 a, 218 b and functions tocollect and transfer diaphragm shear forces to the vertical framecolumns.

Each of the plurality of vertical frame columns 218 a, 218 b can besolid supports of C-shape or U shape cross section, double C or doubleU. Preferably, each of the plurality of vertical frame columns 218 a,218 b are solid supports of I-shape comprising upper and lower beamflanges. At least two of the vertical frame columns 218 a, 218 b arerigidly joined together by the at least one bracing member 220, 320,e.g. a diagonal bracing member 222, 322 and/or a horizontal frame beam.Each of the at least two of the vertical frame columns 218 a, 218 b hasa top end and a bottom end; the bottom end is anchored to a concretefoundation using one or more anchor bolts. Various methods commonlyknown in the art to anchor the bottom end of the vertical frame columnsto the concrete foundation to provide lateral support to the bracedframe against powerful seismic event is applicable in the presentinvention.

Multiple braced frames of the SFRS can be disposed around the peripheryof the grid framework structure (i.e. around each face of the gridframework structure) to form a unitary frame body as shown in FIG. 27and FIG. 28 , i.e. the SFRS forms an exoskeleton supporting the gridframework structure against strong lateral forces as a result of Type Cor Type D seismic events. Alternatively, at least one braced frame canbe disposed to at least one face of the grid framework structure. Thebraced frame of the present invention can be disposed to at least one ofthe four side faces of the cuboid. In the particular embodiment shown inFIG. 27 and FIG. 28 , a braced frame is disposed at each of the fourside faces of the cuboid. The perimeter frame columns 218 a at thecorners of the grid framework structure are braced by at least onehorizontal frame beam 220, 320 extending longitudinally from the top ofeach of the four perimeter frame columns 218 a to form a substantiallyrectangular or square perimeter frame in the horizontal planesurrounding the periphery of the grid.

At least one 218 b of the plurality of vertical frame columns 218 a, 218b can be disposed intermediate of or between two vertical frame columns218 a at the corners of the grid framework structure so as to divide theexoskeleton into a braced frame where at least two vertical framecolumns 218 a, 218 b are braced by at least one diagonal brace 222, 322and a drag strut or collector 232. A drag strut or collector 232 iswhere the at least two vertical frame columns 218 a, 218 b are braced bythe horizontal frame beams 220, 320 at the top of the two vertical framecolumns 218 a, 218 b and functions to collect and transfer diaphragmshear forces to the vertical frame columns 218 a, 218 b. In theparticular embodiment of the present invention shown in FIGS. 27 and 28, the SFRS 215, 315 comprises a braced frame where at least two of theplurality of vertical frame columns 218 a, 218 b are braced by at leastone diagonal brace 222, 322 and a horizontal frame beam 220, 320 to forma drag strut. Also shown in FIG. 27 and FIG. 28 , the at least onediagonal bracing member 222, 322 is disposed to one side of theintermediate vertical support column 218 b to form the braced frame 230and the drag strut 232 is disposed to the other side of the bracedframe. Bracing between the vertical frame columns at the corner of theSFRS and the intermediate vertical support column by at least onediagonal bracing member at each face of the SFRS around the gridframework structure is dependent on the nature of the seismic event,i.e. whether it is a Type C or Type D seismic event. For a more robustrestraint system to cater for Type D seismic events, a braced framecomprising at least one diagonal brace according to the presentinvention is disposed around the periphery of the grid frameworkstructure.

A schematic top view of the seismic grid framework structure accordingto the present invention incorporating the SFRS around the periphery thegrid framework structure is shown in FIG. 30 . The triangles around theperiphery of the grid framework structure represents the braced frame230 comprising at least one diagonal bracing member 222, 322. The dashedlines to the other side of the braced frame 230 around the periphery ofthe grid framework structure represents the drag strut 232 whereby thevertical frames columns is braced by the horizontal frame beam 220, 320.In the particular embodiment of the present invention in FIGS. 27 and 28, the intermediate vertical support columns 218 b is shared between thebraced frame 230 and the drag strut 232. Similarly, the peripheral framecolumn 218 a at the corner of the SFRS is shared between adjacent bracedframe 230 comprising the at least one diagonal bracing member 222, 322or a drag strut 232.

In an alternative embodiment shown in FIG. 31 , the SFRS furthercomprises one or more internal restraint systems 236 within the body ofthe grid framework structure. The additional restraint system 236comprises one or more pairs of vertical frame columns 218 joinedtogether at their upper ends by at least one bracing member 220, 320,222, 322 shown as solid lines internally within the grid frameworkstructure in FIG. 31 . The at least one bracing member can be ahorizontal bracing beam 220, 320 at the top of the pairs of verticalframe columns 218 a, 218 b and/or a diagonal bracing member 222, 322.However, as the additional restraint system 236 within the gridframework structure occupies grid cells that can potentially be used tostore containers, a balance has to be made between the number ofinternal restraint systems that a grid framework structure can occupyand the availability of grid cells in the grid framework structure tostore one or more containers. The preferable option would be for theSFRS 215, 315 of the present invention to be concentrated around theperiphery of the grid framework structure to form an exoskeleton. Thefoot of each of the vertical frame columns 218 a, 218 b are anchored toa concrete foundation such that lateral forces absorbed by the SFRS aretransferred to the floor.

Where the braced frame comprises a K-brace, two diagonal brace members322 are arranged so that a first end of each of the diagonal bracemembers 322 constituting a lower end are arranged at the bottom ends ofthe vertical frame columns 218 a, 218 b. In the particular embodiment ofthe present invention, the first end of each of the diagonal bracingmembers 322 are arranged at the bottom end of the perimeter frame column218 a at the corner of the grid framework structure and the bottom endof the intermediate vertical frame column 218 b (see FIG. 28 ). The twodiagonal brace members 322 are inclined upwardly so that a second end ofeach of the diagonal brace members 322 constituting an upper end meettogether at a peak or apex 324 at a point on the horizontal frame beam320, 220. During a powerful seismic event, the two diagonal bracemembers 322 absorbs the bulk of the lateral forces from the gridframework structure as they are placed under compression and therefore,represents a sacrificial component of the seismic grid frameworkstructure. Thus, the diagonal bracing members 322 and possibly, thebraced frame 230 of the SFRS are easily replaceable after a strongseismic event.

Where the braced frame comprises a cross-brace (see FIG. 27 ), a firstdiagonal brace member and a second diagonal member 222 are formed in anX shape, each of the first diagonal brace member and second diagonalbrace member 222 have opposing ends. The vertical frame columns 218 a,218 b are joined together by the cross brace such that outer ends of thevertical frame columns 218 a, 218 b is rigidly connected to the opposingends of the first and second diagonal brace members 222. Using theterminology of the present invention, the cross brace is disposedbetween the perimeter frame column 218 a at the corner of the gridframework structure and the intermediate vertical frame column 218 bsuch that the outer ends of the perimeter frame columns 218 a and thevertical frame column 218 b are connected to the opposing ends of thefirst and second diagonal brace members 222. As with the K-brace, thebracing members of the cross brace are placed under compression during apowerful seismic event and therefore, represents a sacrificial componentof the seismic grid framework structure. As the bulk of the bendingmoments of the grid framework structure during a powerful seismic eventare transferred to the SFRS 215, 315, the braced frame of the SFRS givesway first before the structural integrity of the grid frameworkstructure fails. In other words, during a powerful seismic event, thestructural restraint system or the SFRS or components of the exoskeletonis/are sacrificed before the structural integrity of the grid frameworkstructure fails. As the SFRS of the present invention surrounds andsupports the grid framework structure, components of the SFRS are easilyreplaceable.

The ends of the bracing members 220, 320, 222, 322 are rigidly connectedto the vertical frame columns 218 a, 218 b of the SFRS by one or morebolts or welds. To provide structural rigidity of the SFRS to absorbstrong lateral forces, the vertical frame columns 218 a, 218 b includingthe perimeter frame columns are bolted to the horizontal perimeter framebeams 220, 320 using a plurality of bolts. The vertical frame columns218 a, 218 b including perimeter frame columns and the horizontal framebeams 220, 320 are generally I—beams that includes top and bottom beamflanges. The vertical frame columns 218 a, 218 b including the perimeterframe columns are bolted to the horizontal frame beam 220, 320 at thebeam flanges. Shims can be disposed between beam flanges of theperimeter frame columns 218 a and the horizontal frame beams 220, 320otherwise known as perimeter frame beams and secured together bysuitable bolts through slotted holes in the beam flanges. In comparisonto the vertical uprights columns or members 116 supporting the grid ofthe grid framework structure, components of the SFRS such as theperimeter frame columns and the horizontal frame beams are moresubstantial in dimension and weight, and largely composed of steel. Forthe avoidance of doubt, the vertical upright columns or upright columns116 are spaced apart within the grid framework structure by one or morespacers and support the grid elements at the intersections where thegrid elements cross.

Maximum lateral forces developed during strong seismic events aregenerally experienced by the grid at the top of the grid frameworkstructure which is subjected to maximum deflection, i.e. during apowerful seismic event, causing the grid to experience side-to-sidelateral forces. Typically, the bending moments of the each of the gridmembers in the grid are concentrated at the intersections where the gridelements (grid elements make up the grid members) cross at the verticalupright column 116. As the grid elements are bolted together and securedto the vertical upright columns 116 via cap plates 150, strong lateralforces at the intersections cause fasteners (e.g. cap plate) which arelargely bolted together to loosen or even break. Whilst the bolts at theintersections can be tightened, this represents a laborious taskconsidering the number of vertical upright columns 116 in a given gridframework structure. What is required is a rigid joint at theintersection where the grid members cross at the vertical uprightcolumns 116.

In an aspect of the present invention, the grid elements are weldedtogether at the intersections 400 instead of being bolted together toprovide a more rigid and sturdy joint than can be provided by boltingalone (see FIG. 32 ). Thus, lateral forces generated in the grid aretransferred as bending moments at the joints where the grid memberscross at each of the upright columns. In accordance with one importantaspect of the present invention and using the terminology of the gridstructure discussed above, the grid elements in the grid are rigidlyconnected together to form at least one Vierendeel truss. As commonlyknown in the art, a Vierendeel truss comprises chords separated by webmembers formed as a series of rectangular frames. The rectangularopenings of Vierendeel trusses make the Vierendeel trusses ideallysuited for a load handling device to move one or more containers storedbelow the trusses, i.e. the grid of the present invention functions asat least one Vierendeel truss assembly.

Depending on the direction of the lateral forces, the chords resistscompression or tension. Vierendeel trusses achieves stability by therigid connection of the web members to the chords. As there are nodiagonal braces, Vierendeel trusses transfer shear from the chords bybending moments at the joints as well as between the chords and webmembers. The distribution of the bending forces across the grid can berepresented by the schematic diagram shown in FIG. 33 . As can be seenin FIG. 33 , maximum bending moments M are concentrated at the joints400 where the grid members or grid elements cross or intersect at thevertical upright columns. By the use of a rigid joint at theintersections or nodes of the grid members, the grid of the presentinvention behaves similarly to a Vierendeel truss whereby shear alongthe grid members are transferred by bending moments at the intersectionsor nodes. The rigid joint 400 at the intersections is provided bywelding the grid elements where they cross. Since the intersections ornodes of the grid are rigidly connected together, the intersections areable to resist shear forces and bending moments developed at theintersections. As the grid of the present invention lies in a horizontalplane, the Vierendeel truss extends across the grid and depending on thedirection of the lateral forces, each of the grid elements behaveseither as a chord under compression or tension or a web.

In comparison to the grid of the grid framework structure discussedabove with reference to FIG. 23 where the grid elements comprises backto back C sections, the grid 250 of the seismic grid framework structureof the present invention comprise tubular beams (see FIG. 32 ). Inpractice, back-to-back C sections which are bolted together areconsidered too weak to work in a seismic region. Tubular beams 460 offerimproved rigidity and strength in comparison to the back-to-back Csections. The tubular cross-sectional profile of the grid members 460offer resistance to bending moments in multiple directions. The tubularbeams 460 making up the grid members also allows the grid members to beeasily welded together at the joints 400 where the grid members cross atthe intersections to from a rigid joint with little or no play. Weldingat the joints offer superior rigidity in comparison to bolts which aremore susceptible to loosening.

The borders of the grid 250 are rigidly connected to the horizontalframe beams 220, 320 that extend from the vertical or peripheral framecolumns 218 a, 218 b of the SFRS at the corners of the grid frameworkstructure such that bending moments experienced by the grid members as aresult of strong lateral forces are transferred to the SFRS which isreinforced by one or more bracing members 220, 320, 222, 322, e.g.diagonal frame braces (braced frames). The distribution of the bendingmoments across the grid structure can be envisaged by the schematicdiagram shown in FIG. 33 . Since maximum bending moments areconcentrated at the intersections 400 where the grid elements cross atthe upright columns 116, it is advantageous that the grid functions as asingle unitary body. In comparison to bolting the grid elements to thecap plate at the intersections discussed above, welding the gridelements together at the intersections in the seismic grid frameworkstructure presents a new problem of the need to handle the entire gridwhich can comprise in excess of 40×40 grid cells and mount it onto thevertical upright columns 116 on site, i.e. in situ. Moreover, buildingregulation limits the amount of welding that can be performed on-sitedue to the risk of fires and exposure to welding fumes. Thus, weldingthe grid elements on site at the intersections does not appear to be apractical proposition.

Such a problem does not exist when the individual grid elements makingup the grid are bolted together via cap plates 150 on site. To overcomethis problem and to meet building regulations, the grid 250 of thepresent invention is sub-divided into a plurality of sub-frames 404 asshown in FIG. 34 , whereby one or more of the sub-frames 404 comprisesat least one grid cell. Multiple sub-frames are assembled together tobuild the grid on site. To comply with building regulations, ideallyindividual sub-frames are bolted together as it is assembled on-site.FIG. 35 show an example of an individual sub-frame 404 forming part ofthe grid 250 according to an embodiment of the present invention.

Bolting the sub-frames together presents a problem as the jointrepresents a weak point in the grid that is susceptible to loosening oreven breakage. To maintain the structural integrity of the grid, theposition of the joint linking individual sub-frames together iscarefully selected to prevent disruption of the grid to function as aVierendeel truss. Locating the joints 402 between adjacent sub-frames404, i.e. mid-cell between adjacent sub-frames, where the bendingmoments are at a minimum or weakest would mitigate external forcesdisturbing the joints linking the individual sub-frames together.Referring back to the distribution of the bending moments along the gridmembers shown in FIG. 33 , bending moments are concentrated at theintersection 400 where the grid members cross at the upright columns anddecreases to a minimum midway between the intersections 402. i.e.mid-cell. Locating the joints 402 halfway between the intersections 400where the grid members (grid elements) cross mitigates excessive lateralforces affecting the linkage or joint between adjacent sub-frames.According to the present invention shown in FIGS. 34 and 35 , linkages402 are formed halfway along the length of the grid elements 460 betweenadjacent sub-frames 404 whereby each adjacent sub-frame comprise atleast one grid cell, i.e. joined mid-cell between adjacent sub-frames404. Extending or overhanging from the at least one grid cell areportions of the grid elements that are configured to join with portionsof the grid elements of an adjacent sub-frame to complete a grid cell.

The linkages joining adjacent sub-frames together comprise a connectionplate 406 that mate with a corresponding connection plate 406 of anadjacent sub-frame 404 to complete a grid cell 54. In the particularembodiment shown in FIG. 35 , the connection plate 406 has a surfacewith the greatest surface area lying perpendicular to the horizontalplane in which the grid lies and comprises one or more holes to receivebolts. When adjacent sub-frames are brought together their correspondingconnection plates 406 mate to complete a grid cell 54. Multiplesub-frames 404 are joined together to form the grid 250 according to thepresent invention.

In order to transfer the shear forces generated axially from the grid tothe SFRS, the border or outer zone 252 of the grid 250 are rigidlyconnected to the horizontal frame beam 220, 320 of the SFRS which act asa bracing member between the vertical frame columns 218 a, 218 b. Thehorizontal frame beam 220, 320 can represent the chords of theVierendeel truss assembly as shown in FIG. 34 . To allow the border orouter zone 252 of the grid 250 to be connected to the horizontal framebeam 220, 320 of the SFRS, the sub-frames 404 at the borders or outerzone of the grid discussed above comprises connection plates or supportplates 408 at the bottom of the sub-frames for connecting to thehorizontal beam (see FIG. 37 ). The connection or support plates 408 canbe welded to the bottom of the sub-frames 404 which are thensubsequently bolted to the horizontal frame beam 220, 320 at the edgesor periphery of the grid as shown in FIG. 38 . The connection plates orsupport plates 408 are positioned mid-cell of one or more sub-frames 404and constitutes the border or outer zone of the grid for supporting thegrid to the periphery bracing structure 215, 315 of the presentinvention as shown in FIG. 38 . The connection or support plates 408 aremounted to the grid elements mid-cell of the sub-frame 404. Thesub-frames 404 are assembled together on the vertical upright columns116 such that one or more sub-frames 404 at the edge of the grid issupported mid-cell by the SFRS of the present invention. In FIG. 38 ,the border or outer zone 252 of the grid has a width of a single gridcell. The connection plate or support plate 408 comprise one or moreholes which align with corresponding holes formed in the top beam flangeof the horizontal frame beam of the SFRS to receive one or more bolts(see FIG. 29 ).

As the seismic grid framework structure of the present invention doesaway with the cap plate 150 to join the grid elements together since thegrid elements are welded together at the intersections, to interconnectthe vertical upright columns 116 to the grid of the seismic gridframework structure of the present invention, the spigot 410 forconnecting to the upright columns 116 are directly mounted to theunderside of the sub-frames 404 at the junction where the grid elementscross (see FIG. 36 ). In the particular embodiment of the presentinvention, a spigot 410 is welded to the underside of the sub-frame atthe junction where the grid elements 460 cross. As shown in FIG. 36 ,four spigots 410 can be seen mounted directly to the underside of thesub-frame 404 at the intersections where the grid elements cross. Thesub-frame 404 is mounted to the vertical upright columns 116 such thatthe spigots protruding from the underside of the sub-frame 404 arereceived in the corresponding hollow centre sections 70 of the uprightcolumns 116 (see FIG. 7 ) in a snap fit arrangement. As a result ofassembling adjacent sub-frames of the present invention comprising atleast one grid cell together in the seismic grid framework structure,the ability to adopt the lamellar pattern in the grid frameworkstructure discussed above is lost. However, welding at the intersectionswhere the grid elements 460 cross more than compensates for the loss ofstructural integrity derived from a lamellar pattern arrangement of thegrid elements discussed above.

As the grid elements 460 of the seismic grid framework structure aretubular or hollow, the surface of the grid elements are not ideallyshaped to mount a track directly onto the grid elements, i.e. littleengagement portions. To provide a track or rail for the load handlingdevice to travel on the grid, a separate track support element 465 ismounted directly to the grid elements 465 (see FIG. 35 ). The tracksupport element 465 allows a track or rail 470 to be fitted to the gridelements 460. Multiple track support elements 465 are distributed on thegrid elements 460 of the sub-frames 404 having a profile that is shapedto receive a track. Thus, in comparison to the grid elements of the gridframework structure discussed above where the track support elements isintegrated into the grid elements of the grid (back to back C sectionshaving a profile to receive a track by a snap fit arrangement), thetrack support elements 465 of the seismic grid framework structure isseparate to the grid elements 460. FIG. 35 shows a top view of thesub-frame 404 according to an embodiment of the present inventionshowing the track support elements 465 mounted directly to the tubulargrid elements 460 and FIG. 39 shows a cross sectional view of thesub-frame showing the engagement of the track 470 to the grid element460 by the track support element 465 according to an embodiment of thepresent invention. Like the track mounted to the grid element of thegrid framework structure discussed above, the track 470 is fitted to thegrid elements 460 in the seismic grid framework structure via the tracksupport element 465 by a snap-fit and/or slid fit arrangement.

In the particular embodiment of the present invention, the track supportelements 465 are welded to the grid elements 460. The seismic gridframework structure of the present invention is not restricted to thetrack support element being a separate component that is welded to thegrid elements of the grid. The track support elements can be integratedinto the body of the tubular grid elements 460. For example, the tracksupport elements can be extruded together with the grid elements as asingle body.

As the track 470 of the seismic grid framework structure is mounted tothe grid elements 460 after the sub-frames 404 are assembled together toform the grid 250, the track 470 can adopt a similar lamellar patterndiscussed above, where sets of tracks elements are arranged on the gridto have a woven-like or brick like appearance, i.e. the track elementsare arranged in a staggered arrangement in the first axial direction andin the second axial direction (the first direction being perpendicularto the second direction) such that adjacent tracks elements in each ofthe first and the second direction are offset by at least one grid cell.Using the language discussed above with respect to the grid frameworkstructure, a set of parallel tracks extend in the first direction and aset of parallel tracks extend in the second direction, the seconddirection being perpendicular to the first direction. A sets of tracksin the first direction is sub-divided into a first sub-set of tracks anda second sub-set of tracks, each of the first and second sub-setcomprising at least one track. The second sub-set of tracks is spacedapart from the first sub-set of tracks in the second direction. Each ofthe first and second sub-set of tracks is divided into a plurality oftrack elements. The track elements are staggered in the first directionsuch that adjacent parallel track elements of the first and secondsub-set of tracks are offset by at least one grid cell.

A similar analogy applies to the set of tracks in the second directionwhereby tracks in the second direction are sub-divided into a firstsub-set of tracks and a second sub-set of tracks, whereby each of thefirst and second sub-set of tracks comprise at least one track. Each ofthe first and the second sub-set of tracks in the second direction issub-divided into a plurality of track elements. The second sub-set oftracks is spaced apart from the first sub-set of tracks in the firstdirection. The track elements are staggered in the second direction suchthat adjacent parallel track elements of the first and second sub-set oftracks are offset by at least one grid cell.

Since lateral forces developed during strong seismic events are largelyabsorbed by the SFRS of the present invention, in a first embodiment ofseismic grid framework structure, the incorporation of the one or morebraced towers discussed above within the grid framework structure of thepresent invention may not be necessary and can be removed, i.e. theseismic grid framework structure comprises a plurality of vertical orupright columns 116 spaced apart by one or more spacers discussedabove—the grid framework structure is supported by the perimeter bracingstructure of the present invention as an exoskeleton. However, theseismic grid framework structure of the present invention is not limitedto removing the one or more braced towers within the grid frameworkstructure and in a second embodiment of the present invention, the SFRScan support a grid framework structure comprising one or more bracedtowers of the present invention incorporated within the grid frameworkstructure as discussed above, i.e. a sub-group of three upright columnslying in the same plane; two upright columns laterally disposed eitherside of a middle upright member, the two laterally disposed uprightmembers are rigidly connected to the middle upright members by aplurality of diagonal braces.

In another aspect of the present invention, the seismic grid frameworkstructure of the present invention can be modularised such that adjacentmodules 514 in an assembly of two or more modules or modular framesshare at least a portion of the SRFS 215, 315 of one or moreneighbouring modular frames. Each of the modules 514 comprise a seismicgrid framework structure 215, 315 discussed above with reference to FIG.27 or FIG. 28 such that each of the modules 514 comprise a predeterminednumber of grid cells and the perimeter bracing structure 215, 315supported by a plurality of vertical frame columns 218 a,b of thepresent invention further supporting the grid. An assembly of two ormodules can be assembled together to increase the storage capacity ofthe overall seismic grid framework structure wherein adjacent modules inthe assembly share at least a portion of the perimeter bracing structureof the present invention, i.e. a first modular frame shares at least aportion of the perimeter bracing structure of a second modular frame,whereby the first modular frame is adjacent the second modular frame. Inother words, adjacent modules share a common bracing member 220, 320,222, 322 supported by at least two vertical frame columns 218 a. Thebracing member includes but are not limited to the horizontal frame beam220, 320 and/or the diagonal bracing member 222, 322.

Sharing of the at least a portion of the SFRS by adjacent modules can beenvisaged in the top plan view shown in FIG. 40 . Four modular grids areshown in FIG. 40 sharing portions of the SFRS of adjacent modular grids.In FIG. 40 , a common braced frame 230 of the SFRS shown as a triangulardrawing is shared between adjacent modular grids 514(a to d). Also thedrag strut 232 shown as a dashed line in FIG. 40 is shared betweenadjacent modules 514(a to d) such that adjacent modules share a commondrag strut 232. As adjacent modules share at least a portion of the SFRSbetween adjacent modules, the grid from adjacent modules are connectedto a common horizontal frame beam 220, 320 such that lateral forcesgenerated within the grid of adjacent modules are transferred to thecommon horizontal frame beam 220, 320. Since the grid is supported atthe borders of the grid in a manner that a portion of the grid overhangsfrom the SFRS, the grids from adjacent modules can be joined together byconnecting the overhangs from adjacent modules. Connection of the gridsbetween adjacent modules can adopt the same linkages joining adjacentmodules together discussed above in respect to FIG. 35 in which theoverhangs at the edge of the grid comprising connection plates orsupport plates 406 that mate with corresponding connection plates orsupport plates 406 of a grid of an adjacent module to complete a gridcell.

Also shared between adjacent modules are the vertical frame columns 218a, 218 b supporting the at least one bracing member 220, 320, 222, 322.By sharing portions of the SFRS between adjacent modules, the externalbracing structures of adjacent modules 514 work together in tandem as aunitary body to deflect lateral forces. Putting it another way, joininggrids 250 from adjacent modules by a common bracing member 220, 320,222, 322, e.g. horizontal frame beam, the multiple adjacent grids 250can function together to form at least one Vierendeel truss such thatlateral forces are transferred across the multiple grids to the verticalframe columns 218 a, 218 b at the periphery of the modules. Theperimeter bracing structure 215, 315 shared between adjacent modules 514also provide internal bracing within the assemblage of the modules 514.The internal bracing includes adjacent modules sharing a common bracedframe 230 and/or a common drag strut 232.

In a known fulfilment centre as shown in FIG. 41 , items and stockrequired to fulfil customer orders are located in containers or storagebins 10, the containers or storage bins can be arranged along aisles. Onthe opposite side of the aisle from the containers or storage bins, aconveyor system is located, the conveyor system carrying customerdelivery bins or containers. The conveyor system is arranged so as topass a proportion of the delivery bins or containers moving on abackline conveyor through pick stations, via station containers, whereitems ordered by a customer are transferred by an operative from astorage bin or container to a customer delivery bin or container. When acustomer delivery container is located at a picking station 600 on theconveyor system, it is paused and an operator selects a required itemfrom a storage bin or container and places it in the customer deliverybin or container. In a known robotic picking station, the storage bin orcontainers is lifted from a stack containing inventory items needed tofulfil a customer order by a load handling device 30. Once lifted by theload handling device 30, the storage bin or container is delivered bythe load handling to an output port above or adjacent a pick station600. At the pick station, the required inventory item or items may bemanually or robotically removed from the storage bin or container andplaced in a delivery container, the delivery container forming part ofthe customer order, and being filled for dispatch at the appropriatetime.

A known fulfilment centre also include various other stations includingbut are not limited to a charge station for charging the rechargebattery powering the load handling devices on the grid, a servicestation to carry out routine maintenance of the load handling device. Toaccommodate any one of the stations or a combination thereof, a separatearea 600 is provided adjacent the grid framework structure 14.Typically, the separate area is provided by incorporating a mezzanine602 supported by vertical beams 604 in amongst adjacent grid frameworkstructures 14 and is generally a standalone structure. The mezzanine 602provides a tunnel to accommodate, for example, one or more pick stationsand/or any one of the above described stations. FIG. 41 shows an exampleof a known ordering picking system comprising a grid framework structureeither side of a tunnel created by a mezzanine 602 for accommodating apick station. The grid 14 a from adjacent grid framework structures 14extend across the top of the mezzanine 602 to connect to a grid eitherside of the mezzanine 602. As is apparent from FIG. 41 , the gridstructure 14 a at the top of the mezzanine 602 is shallower than thegrid framework structure either side of the mezzanine 602, i.e. can onlyaccommodate one or two layers of containers in a stack. As shown in FIG.41 , the grid 14 a that extends across the mezzanine is supported byvertical columns 16 b mounted to the mezzanine and are shorter than thevertical columns either side of the mezzanine. The shorter verticalcolumns 16 b are sized to accommodate only small number of containers ina stack, e.g. one or more containers deep, so as to ensure that the gridlies in a substantial horizontal plane across the mezzanine, i.e. thegrid level is maintained across the mezzanine. Also shown in FIG. 41 ,the mezzanine 602 is supported by separate vertical beams 604. Thevertical beams 604 supporting the mezzanine butts up against the gridframework structure 14 either side of the mezzanine 602. Thus, aseparate standalone framework is necessary to accommodate a mezzanine ina known fulfilment centre.

The seismic grid framework structure of the present invention allows amezzanine 702 to be integrated into the perimeter bracing structure 215,315 and the vertical frame columns 218 of the present invention. Theability to modularise the seismic grid framework structure discussedabove allows the mezzanine 702 to share at least a portion of the SFRSof adjacent modules, i.e. share a common braced frame 230 and/or dragstrut 232 with adjacent or neighbouring modules. A cross sectional viewof an assembly of modules 514 incorporating a mezzanine 702 integratedwithin the assembly is shown in FIG. 42 . As can be seen in FIG. 42 ,the mezzanine 702 shares the perimeter bracing structure 215, 315 andvertical frame columns 218 of adjacent modules 514 such that themezzanine 702 is supported by vertical frame columns 218 a, b supportingadjacent modules 514. Adjacent modules 514 can be a grid frameworkstructure storing one or more containers or storage bins in a stack. Incomparison to the known mezzanine discussed with reference to FIG. 41 ,the mezzanine of the seismic grid framework structure is integratedwithin the SFRS of the present invention so that separate verticalsupport columns to support the mezzanine are not necessary.

To create the mezzanine of the present invention, vertical frame columns218 a, b supporting the grid frame structure of adjacent or laterallydisposed modules 514 are connected together by one or more bracingmembers, e.g. horizontal frame beams to create a mezzanine floor and oneor more diagonal bracing members 722. The vertical support (frame)columns supporting the mezzanine floor can be braced to provide moresupport to the mezzanine structure as shown in FIG. 42 . The combinationof the SFRS incorporating the grid framework structure and the mezzanineprovide a single framework surrounding the assembly.

The SFRS of the present invention is versatile in that the perimeterframe structure 215, 315 is flexible to integrate various otherstructures to the SFRS simply by linking the perimeter frame structuresand vertical frame columns of adjacent modules together using one ormore bracing members, e.g. horizontal frame beams, thereby integratingadditional perimeter frame structures to support a grid and/or anintegrated mezzanine. A top plan view of an assembly of modules, eachcomprising the seismic grid framework structures of the presentinvention either side of a mezzanine structure 700 to accommodate astation is shown in FIG. 43 . As can be seen in FIG. 43 , the mezzanine700 is integrated into the SFRS 215, 315 either side of the mezzanine700 such that the SFRSs of individual modules or modular frames 514 areshared to provide an integrated SFRS encompassing the modules and themezzanine.

There are several advantages of integrating the mezzanine structure 700into the SFRS (FIG. 42 ), as compared to prior art structures such asthe one shown in FIG. 41 . An integrated mezzanine and SFRS removesdesign complexity, and requires fewer parts in the SFRS. The verticalframe columns are shared between the SFRS and the mezzanine, so noseparate vertical beams 604 are required to support the mezzanine. Nobracing is required for the mezzanine. The less complex design of anintegrated SFRS and mezzanine has the further benefit of fasterinstallation time and reduced costs.

Since the space underneath the mezzanine may accommodate pick stations,service stations for maintenance of the load handling devices, or otherfacilities used by human operatives, it is essential that the mezzaninestructure 700 adheres to high standards of safety and complies with allrelevant regulations. If the mezzanine 702 is rigidly connected to theSFRS it behaves more like a building structure, in which case there maybe further requirements to ensure safety and regulatory compliance, suchas cast-in-place floor fixings. An integrated design may therefore notbe suitable for use in all territories.

An alternative to an integrated SFRS and mezzanine structure is toisolate the mezzanine 702 from the SFRS, so that the mezzanine and SFRScan move independently during seismic activity rather than being rigidlyconnected and therefore constrained to move together. This can beachieved by supporting the grid above the mezzanine 702 by a movementjoint 720, transferring load from the grid to the SFRS. As a result, themezzanine is a standalone structure that is independently moveablerelative to the SFRS

FIG. 44 illustrates the grid framework structure and SFRS. The mezzanine702 is connected to the supporting structure by one or more movementjoints 720.

A movement joint is a joint between two parts of a structure, whichallows the parts to move relative to one another while remainingconnected. The SFRS is connected to the mezzanine in the sense that thegrid that extend across the mezzanine from adjacent grid frameworkstructures is mounted to the mezzanine by one or more of the moveablejoints 720. As discussed above with reference to FIG. 41 , the gridextending across neighbouring grid framework structures permits one ormore load handling devices to move across the mezzanine. The SFRS of thecurrent invention may include one or more movement joints between theSFRS and the mezzanine. The movement joint is positioned between thevertical columns and the horizontal members of the grid structure in themezzanine.

A sliding bearing is one kind of movement joint. FIG. 45 illustrates onepossible embodiment of a sliding bearing. A lower plate 710 is mountedon top of an upright column 116 (not shown). The lower plate 710 isattached to a lower backing plate 711. A pad 712 is adhered to the lowerbacking plate, and in turn a lower bearing pad 713 is adhered to the pad712. The lower bearing pad 713 is configured to be in contact with andslide relative to an upper bearing pad 714. The bearing pads 713, 714may be made of Teflon, PTFE, or other suitable material. The upperbearing pad 714 is adhered to an upper backing plate 715, which isattached to an upper plate 716. A guardrail 717, during operation,restricts the motion of the lower bearing pad 713 relative to the upperbearing pad 714 such that the bearing pads 713, 714 remain in contact.The lower bearing pad 713 and the upper bearing pad 714 are configuredto be in contact along a contact length 718 during operation. A movementlength 719 is the range of movement either side of the central position.It will be appreciated that the contact length 718 and the movementlength 719 illustrate the range of motion in a first dimension, but themovement joint may also permit relative motion in a second dimensionsubstantially perpendicular to the first.

The lower plate 710 may be mounted on top of an upright column 116. Theupper plate 716 may be attached to the underside of the grid extendingacross the mezzanine.

It will be appreciated that there are alternative methods of attachingthe upper plate 716 to the underside of the grid. Two options aredescribed here.

FIG. 46 illustrates a movement joint 720 where the upper plate 716 ofthe movement joint is attached directly to the underside of a gridmember 118, 120. The lower plate 710 is mounted on top of a verticalcolumn 116. Advantageously, this is a simple configuration with fewextra parts. For example, the upper plates 716 can be connected to theunderside of the grid members by welding. The grid cells adjacent to themovement joint 720 may not be used for storage.

FIG. 47 illustrates a movement joint 720 where the upper plate 716 ofthe movement joint 720 extends across the breadth and width of a gridcell 54. Advantageously, this configuration allows a greater contactlength 718 and a greater movement length 719 than the configuration ofFIG. 46 , resulting in a greater contact area and greater range ofrelative motion between the mezzanine and the SFRS. The lower plate 710is mounted on top of a vertical column 116.

FIG. 48 illustrates a top view of the movement joint of FIG. 47 . Theupper plate 716 of the movement joint is reinforced with a beam 721 toreinforce and stiffen the upper plate 716. The beam 721 is illustratedhere as an I-beam, but other types of beam can also be used. The upperplate 716 is attached to the horizontal grid members 118, 120 by meansof brackets 723, which are bolted to the upper plate 716 and the gridmembers 118, 120. Although this configuration has the disadvantage thatit requires more parts and more assembly operations than theconfiguration of FIG. 46 , a movement joint can be placed in everyalternate grid cell, leaving the grid cells in between the movementjoints free to be utilised for storage.

The advantage of isolating the grid above the mezzanine from movement asa result of movement from a neighbouring grid framework structure can beapplied to the grid framework structure described with reference to FIG.6 a and the SFRS described above to isolate ground movement from thegrid mounted thereon. For example, one or more movement joints 720discussed above can be interposed between the grid members and thevertical columns at the intersections of the grid members. The movementjoint can be placed between the cap plate and the top of the verticalcolumns. Thus, the grid is isolated from movement of the verticaluprights as a result of ground movement by the one or more movementjoints. Ground movement can be as a result of a seismic event to simplyfrom a passing vehicle, e.g. train. Equally, one or more movement jointscan be interposed between the grid members and the vertical columns inthe SFRS arrangement described with reference to FIGS. 27 and 28 . In anevent of ground movement, the one or more movement joints interposedbetween the vertical columns and the grid will dampen the groundmovement. Moreover, any induced oscillation of the grid will help tocounteract and absorb the kinetic energy development during oscillationof the vertical columns and/or containers stored therein as a result ofground movement.

Due to the versatility of the SFRS of the present invention, otherstructures can be integrated into the SFRS of the present invention. Toprevent a load handling device overrunning the grid, crash barriers aremounted around the edge of the grid to absorb the impact when a loadhandling device hits the crash barrier. Due to the weight of a loadhandling device which can be in excess of 100 kg, the crash barriersneed to be mounted and supported by a separate structure comprisingseparate vertical support frames adjacent the grid. The structuresupporting the crash barrier is not fixedly attached to the gridframework. This is so the crash barrier do not impart damage to the gridframework structure should a load handling device inadvertently crashinto the crash barrier. Detail of the crash barrier known in the art isfurther discussed in WO2017/153563 (Ocado Innovation Limited). InWO2017/153563 (Ocado Innovation Limited), the structure supporting thecrash barrier needs to absorb the impact from one or more load handlingdevices and comprises one or more bracing assemblies.

However, since the SFRS is functioned to restrain the grid frameworkstructure in an event of a powerful seismic event, the SFRS is versatileto accommodate one or more crash barriers, i.e. the crash barrier can bemounted directly to the perimeter bracing structure. The SFRS of thepresent invention can be sufficiently robust to absorb the impact fromone or more load handling device hitting the crash barrier mounteddirectly to the perimeter bracing structure of the SFRS. Thus, unlikeknown grid structures where the crash barrier is mounted to a separateframework structure adjacent the grid framework structure carrying theload handling device, the crash barrier can be integrated into the SFRSof the present invention.

Welding the grid elements 460, which are largely tubular beams, togethercreates a rigid structure that is able to absorb a certain degree ofimpact. Due to the structural rigidity and strength of the grid 250 ofthe seismic grid framework structure of the present invention, which islargely attributable to the perimeter bracing structure supporting thegrid and the vertical frame columns, the grid is sufficiently stable tocarry or mount a crash barrier without disrupting the structuralintegrity of the grid structure in the event of a load handling devicecrashing into the crash barrier. In a particular embodiment of thepresent invention, a crash barrier is mounted directly to the grid 250,i.e. at the edge of the grid. The crash barrier 800 is located atvarious positions around the edge of the grid 250 and is configured toabsorb shocks when a load handling device inadvertently overruns thegrid. In the particular embodiment of the present invention shown inFIG. 49 , the crash barrier 800 comprises one or more impact absorbers802 mounted to a crash beam 804 positioned around the edge of the grid250. The impact absorber 802 is composed of a material that isconfigured to dissipate energy when impacted and thereby, help tomitigate excessive damage to the load handling device in an event of acrash. Examples of materials that dissipate energy when impacted includebut are not limited to a resilient material, e.g. rubber, or asacrificial material such as sacrificial honeycomb aluminium. In theparticular embodiment of the present invention shown in FIG. 49 , theone or more impact absorbers 802 has a honeycomb structure composed ofaluminium that is configured to collapse when impacted. The one or moreimpact absorbers 802 are mounted to a frame which is subsequentlymounted to the grid 250. The frame comprises the crash beam 804 mountedto the edge of the grid 250 via one or more posts 806. The one or moreimpact absorbers 802 are mounted to the crash beam 804 so as to extendinwardly to overhang or span over one or more grid cells. Should a loadhandling device inadvertently travel towards the edge of the grid, toprevent a load handling device inadvertently overrunning the edge of thegrid 250, the load handling device crashes into the crash barrier 800.As the grid 250 in the seismic grid framework structure is largelycomposed of tubular beams 460 (See FIG. 32 ) that are rigidly connectedtogether to resist lateral forces in a seismic event, the crash barrier800 of the present invention can be mounted directly to the grid 250 asshown in FIG. 49 .

Various modifications and variations of the illustrative embodiments, aswell as other embodiments of the grid framework structure, which areapparent to persons skilled in the art, are deemed to lie within thescope of the present invention as defined by the claims. For example, inthe case where the seismic grid framework structure is modularised tocomprise an assembly of two or more modules or modular frames, each ofthe modules or modular frames comprising a predetermined number of gridcells and the perimeter bracing structure 215, 315 of the presentinvention supporting the grid as discussed above, the two or more of themodules or modular frames can share a common crash barrier havingfeatures discussed with reference to FIG. 49 . In this case, the crashbarrier 800 is mounted to the edge of an assembly of the two or moremodules or modular frames, i.e. at least partially surrounds an assemblyof two or more modules or modular frames.

1.-29. (canceled)
 30. An earthquake restraint grid framework structure comprising: a grid framework structure configured for supporting a load handling device operative to move one or more containers in a stack; a series of intersecting grid members arranged to form a grid having a plurality of substantially rectangular frames in a horizontal plane, each of the substantially rectangular frames constituting a grid cell, said grid being supported by a plurality of upright columns at each of the intersections of the series of intersecting grid members to form a plurality of vertical storage locations for containers to be stacked between the upright columns and be guided by the upright columns in a vertical direction through the plurality of substantially rectangular frames; and an exoskeleton having a plurality of vertical frame columns braced by at least one bracing member, said grid being further supported by the exoskeleton to form a seismic restraint system (SFRS).
 31. The earthquake restraint grid framework structure of claim 30, wherein the grid comprises: a border or an outer zone, wherein the border or outer zone of the grid is supported by the exoskeleton.
 32. The earthquake restraint grid framework structure of claim 31, wherein the at least one bracing member extends from each of the plurality of vertical columns to form a perimeter bracing structure to further support the grid.
 33. The earthquake restraint grid framework structure of claim 32, wherein the at least one bracing member is inwardly positioned from an edge of the grid such that the outer zone or border of the grid inwardly extends across the at least one bracing member.
 34. The earthquake restraint grid framework structure of claim 33, wherein a width of the border or outer zone of the grid constitutes a single grid cell such that the at least one bracing member is inwardly positioned within the border or outer zone of the grid.
 35. The earthquake restraint grid framework structure of claim 32, wherein the border or outer zone of the grid constitutes an edge of the grid such that the grid is supported around a periphery of the grid by a perimeter bracing structure.
 36. The earthquake restraint grid framework structure of claim 30, wherein the series of intersecting grid members are rigidly connected together at the intersections to form at least one Vierendeel truss assembly.
 37. The earthquake restraint grid framework structure of claim 31, wherein the grid is attached between pairs of bracing members along the border or outer zone of the grid to form at least one Vierendeel truss assembly so as to provide lateral support of the grid framework structure in a side-to-side direction.
 38. The earthquake restraint grid framework structure of claim 30, wherein the at least one bracing member is a horizontal frame beam, wherein said horizontal frame beam extends between at least two of the plurality of vertical frame columns to form a drag strut.
 39. The earthquake restraint grid framework structure of claim 30, wherein the at least one bracing member is a diagonal bracing member, wherein said diagonal bracing member extends between at least two of the plurality of vertical frame columns.
 40. The earthquake restraint grid framework structure of claim 39, wherein the diagonal bracing member comprises: a first diagonal bracing member and a second diagonal bracing member.
 41. The earthquake restraint grid framework structure of claim 40, wherein the at least one bracing member comprises: a horizontal frame beam, and wherein the first diagonal bracing member, the second diagonal bracing member and the horizontal frame beam are arranged to form a K brace wherein said K brace is disposed between the at least two of the plurality of vertical frame columns.
 42. The earthquake restraint grid framework structure of claim 40, wherein the first diagonal bracing member and the second diagonal bracing member are arranged in a cross brace, wherein said cross brace is disposed between the at least two of the plurality of vertical frame columns such that the at least two vertical frames columns are joined together by the cross brace.
 43. The earthquake restraint grid framework structure of claim 31, wherein the plurality of vertical frame columns comprises: four vertical frame columns arranged at four corners of the grid framework structure, the at least one bracing member extending from each corner at a top of the four vertical frame columns to form a substantially rectangular or square perimeter frame within or around the border or outer zone of the grid.
 44. The earthquake restraint grid framework structure of claim 43, wherein the plurality of vertical frame columns comprises: at least one vertical frame column disposed between at least two of the four vertical frame columns at the corners of the grid framework structure, and wherein the at least one bracing member extends between at least one of the four of vertical frame columns at the corners of the grid framework structure and the at least one vertical frame column between the at least two of the four vertical frame columns at the corners of the grid framework structure.
 45. The earthquake restraint grid framework structure of claim 30, wherein the series of the intersecting grid members include welds at their intersections.
 46. The earthquake restraint grid framework structure of claim 30, wherein the at least one of the series of intersecting grid members is a tubular beam.
 47. The earthquake restraint grid framework structure of claim 30, wherein the grid is sub-divided into a plurality of interconnected sub-frames, each of the plurality of interconnected sub-frames comprising: at least one grid cell.
 48. The earthquake restraint grid framework structure of claim 47, wherein adjacent sub-frames are joined together by a joint located between intersections of adjacent sub-frames.
 49. The earthquake restraint grid framework structure of claim 48, wherein the joint is substantially mid-way between the intersections.
 50. The earthquake restraint grid framework structure of claim 30, wherein a rail or track is mounted to the grid for guiding movement of load handling devices on the grid.
 51. The earthquake restraint grid framework structure of claim 30, wherein at least a portion of the grid is supported to the plurality of vertical columns by one or more moveable joints such that the at least portion of the grid and the one or more of the vertical columns are configured to move independently relative to each other during seismic activity.
 52. An assembly of two or more modular frames, wherein each of the two or more modular frames comprises: an earthquake restraint grid framework structure of claim 30, wherein adjacent modular frames are arranged in the assembly such that at least a portion of the SFRS of the two or more modular frames is shared between adjacent modular frames.
 53. The assembly of claim 52, wherein a grid of adjacent modular frames extends across an exoskeleton structure of adjacent modular frames.
 54. The assembly of claim 52, comprising: at least one mezzanine disposed between two or more modular frames such that a grid of the two or more modular frames extends across the mezzanine.
 55. The assembly of claim 54, wherein the at least one mezzanine is supported by the two or more modular frames such that the mezzanine shares at least one vertical frame column common between the two or more of the modular frames.
 56. The assembly of claim 54, wherein the mezzanine is connected to the two or more modular frames by one or more movement joints, such that the mezzanine and the one or more modular frames are configured to move independently relative to each other during seismic activity.
 57. A storage system comprising: i) an earthquake restraint grid framework structure of claim 30; ii) a plurality of stacks of containers arranged in storage columns located below the grid, wherein each storage column is located vertically below a grid cell; iii) a plurality of load handling devices for lifting and moving containers stacked in the stacks, the plurality of load handling devices being remotely operated to move laterally on the grid above the storage columns to access the containers through the substantially rectangular frames, wherein each of said plurality load handling devices includes: a) a wheel assembly for guiding the load handling device on the grid; b) a container-receiving space located above the grid; and c) a lifting device arranged to lift a single container from a stack into the container-receiving space.
 58. A storage system comprising: i) an assembly of claim 52; ii) a plurality of stacks of containers arranged in storage columns located below the grid, wherein each storage column is located vertically below the grid cell; iii) a plurality of load handling devices for lifting and moving containers stacked in the stacks, the plurality of load handling devices being remotely operated to move laterally on the grid above the storage columns to access the containers through the substantially rectangular frames, wherein each of said plurality load handling devices includes: a) a wheel assembly for guiding the load handling device on the grid; b) a container-receiving space located above the grid; and c) a lifting device arranged to lift a single container from a stack into the container-receiving space. 